Brake cylinder comprising a mechanical stop

ABSTRACT

A brake cylinder configured to provide braking signaling to an automotive simulator, the brake cylinder includes a damper housing, a resilient damper arranged within the damper housing and a piston configured to move a block in the axial direction at least partially into the damper housing towards said resilient damper. The block comprises a mechanical stop configured to limit the axial movement of the piston in the axial direction. The brake cylinder further has a sensor configured to measure a response to movement of said piston and send a signal to a processor indicative of that movement. The brake cylinder is configured to be connected to a brake pedal. The mechanical stop divides the braking process into two phases a first phase where the pedal can be depressed and a second phase where the pedal cannot be pressed further due to the mechanical stop. In one variant the brake cylinder is a purely mechanical system with only the damper housing or in combination with a single cylinder chamber. Alternatively, the described cylinder chamber is a slave chamber for use in a hydraulic brake cylinder also including a master chamber in fluid connection with the slave chamber via a channel.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to European Patent Application No.21168955.9 filed on Apr. 16, 2021. The application claims priority fromU.S. application Ser. No. 17/445,638 filed on Aug. 23, 2021. Thedisclosures of the above-referenced applications are expresslyincorporated herein by reference in their entirety.

BACKGROUND Field of the Invention

Systems and devices consistent with the present disclosure generallyrelate to a brake cylinder comprising a mechanical stop. Moreparticularly, systems and devices consistent with the disclosure relateto a brake cylinder comprising a mechanical stop for use in automotivesimulators that is both cost effective to produce and provides authenticfeedback when in use.

Discussion of the Related Art

Automotive simulation systems that simulate the experience of driving acar are used for both video gaming purposes as well as for trainingpurposes for persons involved in driving, such as racing car drivers. Toeffectively achieve these video gaming and training purposes, thesimulation provided by these automotive simulation systems must be ableto replicate the experience of a real car with a high degree of accuracyand authenticity. However, designing an automotive simulation systemthat achieves a high degree of accuracy and authenticity is difficultand expensive to produce.

In order to make the simulation as close to reality as possible (i.e.,with a high degree of accuracy and authenticity), it is important thatin addition to the visual experience, user interface equipment such assteering wheels and brake systems have to be equal, or as close aspossible, to that which is experienced in a real car. This allows formaximum learning potential in automotive simulation systems used fortraining and maximum entertainment emersion potential in automotivesimulation systems used for video gaming purposes. Regarding brakesystems in automotive simulation systems, it is not just important thatthe mechanical elements, such as the brake pedals, look like those andfeel like those of a real car, it is also important to have the tactileresponse (e.g., the feedback and feel of pressing the brake pedal) in anautomotive simulation system be the same as or similar to that which isexperienced in a real car.

In conventional brake systems that are used in automotive simulationsystems, depressing a brake pedal compresses a liquid (such as oil) in achamber of a main brake cylinder. The elevated pressure in this chamberis then transferred to a slave cylinder where the pressure is measured.By converting the measured pressure in this slave cylinder, anelectrical signal is generated which can be used as input to asimulation program of the automotive simulation system. These componentsof conventional brake systems take up a lot of space within the brakesystems, and the incorporation of multiple interconnected chambersconnected via tubes makes manufacturing/mass production of suchconventional brake systems expensive.

Conventional brake systems that are used in automotive simulationsystems and which are based on hydraulics are also prone to leak due tomany fittings and connections that are each regions where fluid may leakout of the system. Fluid leakage causes the performance of the brakingsystem to deteriorate over time and is a hazardous risk near electronicsthat may short-circuit due to leaking fluids.

One solution to this issue known in the art is to make braking systemwhich are purely mechanical having no hydraulics and thus no fluid whichcan leak from the system. Such system relies on resistance solely fromthe compression and elastic deformation of a resilient piece ofmaterial. While such a solution solves the risk of leakage and ischeaper and simpler to produce, the tactile and physical feedback issignificantly different from that of a real car.

In view of the foregoing, it is desirable to create a brake system thatis simple and inexpensive to produce while maintaining the look and feelof a brake system in a real car. The brake cylinder comprising amechanical stop for an automotive simulation system is directed toovercoming one or more of the problems set forth above and/or otherproblems of the prior art.

SUMMARY OF THE INVENTION

There is described a brake cylinder configured to provide brakesignaling to an automotive simulator, the brake cylinder comprising: apiston configured to move in an axial direction; a dampening deviceconfigured to provide resistance to the piston when the piston moves inan axial direction toward the dampening device; at least one sensorconfigured to measure a response to movement of said piston and send asignal to a processor of the automotive simulator indicating of thatmovement, wherein said piston comprises a mechanical stop configured tolimit said axial movement of the piston in the axial direction.

By axial movement of the piston is understood that it can move back andforth along its longitudinal axis, without movement in a transversedirection with respect to the longitudinal axis of the piston. Thus, ifthe piston is moving within a chamber or a hollow, e.g. inside thedamper housing, in a variant the chamber and the piston are arrangedcoaxially such that the piston may translate back and forth within thatchamber without the piston colliding with the wall of the chamber due totransverse or angled movement.

By a resilient damper is understood a damper which may be compressedunder the force of the block and which will spring back into shape oncethe pressure is decreased and/or removed. Such a resilient damper mayfor example be a rubber structure or a type of spring.

In some variants the mechanical stop is made of a rigid material. Inanother variant the block and the mechanical stop are made of the samematerial, such as a rigid material.

The brake cylinder is adapted for use in a braking system including abrake pedal. The brake cylinder according to the disclosure may be ofvarious types. It may be a mechanical brake cylinder including only adamper housing or a damper housing in combination with a cylinderchamber. Different types of sensors may be used for determining theamount of force applied to the brake pedal and in turn the amount ofmovement of the piston. Such sensors for the mechanical brake cylindermay for example be a load cell using a strain gauge, a rotarypotentiometer or a Hall effect sensor in combination with a magnet. Inother variants the brake cylinder may be part of a hydraulic systemcomprising multiple chambers, such as both a slave cylinder chamberconfigured and a master cylinder chamber, in addition to a damperhousing. In the hydraulic variant, the two chambers are in fluidcommunication via at least one channel. In such a configuration thesensor may be a pressure sensor in fluid communication with the chambersof the brake cylinder. Any known type of sensor which is suitable fordelivering a signal correlated to the pressure applied to the pedal maybe used. In the automotive simulation the braking effect achieved for agiven detection of the sensor may be adjusted based on user preferenceand/or other factors of the simulation such as grip on a simulatedsurface and/or the type of vehicle simulated. In all discussedembodiments of the invention, it is possible to use one or more sensors,hence it is possible to have multiple sensors either of the same type orof various known types used within a single brake cylinder regardless ofwhether there is a hydraulic or a mechanical brake cylinder.

In one embodiment the mechanical stop is configured to limit the axialmovement of the block in the direction towards the resilient damper.

In another embodiment the mechanical stop is configured to limit theaxial movement of the block by contact between the mechanical stop andthe damper housing.

The mechanical stop of the block enables the braking process to bedivided into two phases. During the first phase of the braking process,i.e. before the mechanical stop is engaged to limit the axial movementof the piston, the pedal can be moved, i.e. the pedal can be depressed.During the second phase of the braking process, i.e. once the stop iscontacted, the mechanical stop limits the further movement of the pedal.By the mechanical stop limiting the further movement of the piston isunderstood an abrupt increase in the force required to move the pedal apredetermined distance compared to force required to move the pedal thesame predetermined distance before the engagement of the mechanicalstop. In some embodiments the mechanical stop will completely preventthe further movement of the pedal, i.e. movement of the pedal wouldrequire permanent deformation of the mechanical stop. In otherembodiments it will be possible to move the pedal in the second phase aswell although engagement the mechanical stop will cause the abrupttransition to an increased resistance felt by the user as force isapplied to the pedal, thereby requiring an increased force to depressthe pedal further. In embodiments the brake cylinder is configured suchthat the length of the first phase can be adjusted, by adjusting thedistance the pedal has to travel before the mechanical stop is engagedfor example by adjusting the space in the damper housing for the damperand exchanging the damper with one of different dimension. The two-phasebraking process is equivalent to the feeling of a real pedal in a carwhere the resistance will change during the braking process.

The benefits of two-phase braking are achieved by the presence of amechanical stop regardless of whether the brake cylinder is a lonemechanical cylinder or a slave cylinder in combination with a mastercylinder in a hydraulic system. In hydraulic systems having two chambersthe two-phase operation enabled by the mechanical stop is achievedindependently of the arrangement of the master chamber and the slavechamber relative to each other, e.g. if they are integrated int eh samecylinder housing or if they are two separate chamber, or if they areparallel or located at an angle relative to each other.

The mechanical stop and the two-phase braking process is also beneficialin a mechanical system with a single cell, as the response the user getsfrom the pedal when using a brake cylinder with a mechanical stop isvastly improved in that it is more akin to that from a real car, whilethe bake cylinder for the simulation system remains cheap and simple tomanufacture.

The mechanical stop and the two-phase braking process is beneficial in ahydraulic brake cylinder as it provides the user with feedback akin tothat in a real car using a hydraulic brake system and having a two-phasebraking process. In addition to the realistic tactile feedback thesystem has high precision as the increase in pressure within the brakecylinder chambers in the second phase of the braking process can bemeasured and provide the simulation system with feedback on the brakingforce throughout the braking process.

Hence, it is to be understood that when the brake cylinder is describedthe damper housing may stand alone or be connected to the end of a brakecylinder chamber. When connected to a brake cylinder chamber it may be amechanical cylinder chamber which or a slave cylinder of the hydraulicsystem. This includes that the brake cylinder chamber may be the slavecylinder chamber, the piston may be the slave piston features such as aslave cylinder rod and a slave cylinder piston element. Alternatively,the brake cylinder may be mechanical brake cylinder with a mechanicalcylinder chamber and a mechanical cylinder rod and a mechanical pistonelement.

It is to be understood that by the damper housing being coaxiallyadjacent the cylinder chamber is understood that the cylinder chamberand the inner volume of the damper housing where the damper is arrangedare coaxial such that the piston may continue its translation from thecylinder chamber into the inner volume of the damper housing. The outershape of the damper housing may vary between embodiments and may forexample be asymmetric in a way where the entirety of the damper housingis not coaxial with the cylinder chamber, as long as the inner volume ofthe damper housing is.

In one embodiment there is described a brake cylinder configured toprovide braking signaling to an automotive simulator, the brake cylinderincluding a brake cylinder chamber, a damper housing arranged coaxiallyadjacent to the brake cylinder chamber, a resilient damper arrangedwithin the damper housing; a piston at least partially disposed withinthe cylinder chamber, the piston being configured to translate in theaxial direction within the cylinder chamber and at least partially intothe damper housing; translation away from the damper housing istranslation in a first direction and translation towards the damperhousing is translation in a second direction; a sensor configured tomeasure a response to movement of the piston affected by a brake pedaland send a signal to a processor indicating of that movement; wherein,the piston includes a block, the block comprising a mechanical stopconfigured to limit axial movement of the piston in the second directionvia contact with the damper housing.

In one embodiment there is described a brake cylinder including a brakecylinder housing including (i) a master cylinder chamber, (ii) a slavecylinder chamber, and (iii) a wall disposed between the master cylinderchamber and the slave cylinder chamber, the wall defining at least oneopening configured to provide fluid communication between the mastercylinder chamber and the slave cylinder chamber; a master piston atleast partially disposed within the master cylinder chamber, the masterpiston configured to pressurize fluid in the master cylinder chamberwhen a brake pedal is pressed; a slave piston at least partiallydisposed within the slave cylinder chamber; and a pressure sensordisposed in fluid communication with the slave cylinder chamber, thepressure sensor configured to measure pressure in the slave cylinderchamber and send a signal to a processor indicating of movement of thebrake pedal; wherein, when pressurizing fluid in the master cylinder,the master piston is configured to drive fluid from the master cylinderchamber to the slave cylinder chamber via the at least one opening toincrease pressure in the slave cylinder chamber.

It is to be understood that in variants with two-cylinder chambers, i.e.a master cylinder chamber and a slave cylinder chamber, the brakecylinder is a hydraulic closed system the pressure is the same insidethe enclosure. Thus, the pressure sensor may be located anywhere inconnection with the hydraulic system. For example the pressure is thesame within the slave cylinder chamber and the master cylinder chamberthe pressure sensor physically arranged to be in communication witheither of the chambers as it will be in pressure communication with bothchambers, and the rest of the brake cylinder, regardless.

In one embodiment, there is described a brake system including a base; abrake pedal pivotably connected to the base; and a brake cylinderpivotably connected to the brake pedal, the brake cylinder including: abrake cylinder housing including (i) a master cylinder chamber, (ii) aslave cylinder chamber, and (iii) a wall disposed between the mastercylinder chamber and the slave cylinder chamber, the wall defining atleast one opening configured to provide fluid communication between themaster cylinder chamber and the slave cylinder chamber; a master pistonat least partially disposed within the master cylinder chamber, themaster piston configured to pressurize fluid in the master cylinderchamber when the brake pedal is depressed; a slave piston at leastpartially disposed within the slave cylinder chamber; and a pressuresensor disposed in fluid communication with the slave cylinder chamber,the pressure sensor configured to measure pressure in the slave cylinderchamber and send a signal to a processor indicating of movement of thebrake pedal; wherein, when pressurizing fluid in the master cylinderchamber, the master piston is configured to drive fluid from the mastercylinder chamber to the slave cylinder chamber via the at least oneopening to increase pressure in the slave cylinder chamber.

As described above, the brake cylinder includes a brake cylinder housingwith a master cylinder chamber and a slave cylinder chamber. Thecylinder chambers are separated by the wall defining openings allowingliquid to pass from the master cylinder chamber to the slave cylinderchamber. The master cylinder chamber includes the master piston forconnecting to a brake pedal (or similar interface), and the masterpiston when pushed is adapted to force liquid from the master cylinderchamber to the slave cylinder chamber via the openings. The slavecylinder chamber comprises a slave piston which is adapted to be pushedwhen liquid enters from the master cylinder chamber into the slavecylinder chamber.

In some variants the fluid communication between the master cylinderchamber and the slave cylinder chamber may be provided by anotherchannel than the one or more openings in the wall between the chambers.For example, a channel may be provided in some other part of the brakecylinder, such as the outer wall, rather than the separating wall.Another example is by the presence of a tube extending externally fromthe brake cylinder, for example running along the outer surface of thebrake system or connecting the master cylinder chamber and the slavecylinder chamber via another piece of equipment arranged in the fluidpath of the channel.

The master cylinder chamber and the slave cylinder chamber are housed ina common brake cylinder housing. The master cylinder chamber includesthe master piston which can affect a fluid which again can affect theslave piston in the slave cylinder chamber. The fluid may be an oil oranother low-compressible liquid used in braking systems. The mastercylinder chamber and the slave cylinder chamber are mutual connected viaat least one opening. In a variant the master cylinder chamber and theslave cylinder chamber are substantially parallel. The two chambers areonly separated by a wall constituting a part of the cylinder chamberwall in both cylinder chambers. The master piston is connected to thebrake pedal via a master cylinder rod, which can affect movement of themaster piston. In one embodiment, the master piston and the slave pistonare arranged such that in their respective cylinder chambers, the slavepiston is pushed in an opposite direction of the master piston when themaster piston is pushed. In this manner a very compact design of thebrake cylinder housing is achieved.

In an alternative embodiment the brake cylinder of the brake cylindersystem comprises a master cylinder chamber and a slave cylinder chamberwhich are arranged separately, i.e. that are not integrated in the samebrake cylinder housing. The working principle of the braking systemremains the same. In such a case the master brake cylinder chamber andthe slave cylinder chamber will be in fluid communication through one ormore external channels. While less compact such a solution with twoseparate chambers provide more flexibility in the placement of thechambers as may be needed for space constraints at the simulationset-up.

In one embodiment of the brake cylinder, the master cylinder is arrangedwith an internal master cylinder rod engaging with a cavity in themaster piston and with a master cylinder spring surrounding the internalmaster cylinder rod at least along the length of the rod. The internalmaster cylinder rod may be attached to the master cylinder at theopposite end of the entrance of the master cylinder rod connected to thebrake pedal. The master cylinder rod extends along the length of themaster cylinder chamber into a cavity of the master piston that extendsinto the master cylinder rod. The internal master cylinder rod issurrounded by a master cylinder spring along its entire length and themaster cylinder spring continues into the cavity of the master cylinderrod connected with the brake pedal. Thus, the master cylinder spring mayserve to bring the brake pedal back to its initial position after it hasbeen pushed. Together the internal master cylinder rod and the mastercylinder spring serve to control the movement of master piston in themaster cylinder chamber.

In one embodiment the slave cylinder is arranged with an internal slavecylinder rod engaging with a cavity in the slave piston and with a slavecylinder spring surrounding the internal slave cylinder rod at leastalong the length of the rod. The internal slave cylinder rod may beattached to the slave cylinder at the end toward which the slave pistonis moved when the brake is depressed. The slave piston element isconnected with a damping system via a slave cylinder rod. The internalslave cylinder rod is surrounded by a slave cylinder spring which servesto bring the slave piston back to an unloaded position after the brakehas been released. In combination, the internal slave cylinder rod andthe slave cylinder spring serve to control the movement of slave pistonin the slave cylinder chamber. In one embodiment, the slave cylinderspring and the internal slave cylinder rod continue into at least a partof the cavity in the slave piston. The slave cylinder spring may alsocontinue into a cavity in the slave cylinder rod. Thus, the slavecylinder spring may serve to control the movement of the slave cylinderrod.

The unloaded position is considered the default position of the brakecylinder system as well as for the brake pedal; this can also beconsidered the released orientation of the system. The terms “defaultposition”, “unloaded position” and “released orientation” will be usedinterchangeably throughout the application. This unloaded defaultposition is also considered the first position of the system, hence whenthe system is in the unloaded position or default position of thesystem, the master piston is in the first master position and the slavecylinder is in the first slave position.

The master cylinder chamber may include a stop for stopping the masterpiston. The stop may be mounted at the opposite end of the entrance ofthe master cylinder rod. Thus, the stop is mounted at the same end inthe master cylinder chamber as the internal master rod. The stop maysurround the spring and the internal rod along its length.

In other variants the end wall of the master cylinder chamber mayfunction as a stop for the master cylinder piston element and noadditional master cylinder stop member is necessary in the mastercylinder chamber.

The position where the master is in contact the stop or the end wall,i.e. via contact between the piston element and the stop or end wall,the master piston is in the second master position.

Also, the slave cylinder chamber may include a stop for stopping theslave piston. However, this stop is mounted in the opposite end of wherethe internal slave rod is mounted. The stop serves to stop the movementof the slave piston in the direction of the dampening device.

In other variants the end wall of the slave cylinder chamber mayfunction as a stop for the slave cylinder piston element and noadditional slave cylinder stop member is necessary in the slave cylinderchamber.

The position where the slave piston is in contact with the stop, i.e.the slave cylinder stop member, or the end wall or the movement of theslave cylinder is stopped by the mechanical contact between a mechanicalstop of a block connected to the slave cylinder rod, the slave piston isin the second slave position. It is to be understood that a damperpiston is a specific variant of a block. Both the block and the damperpiston serve the purpose of contacting and compressing the dampener aswell as comprising the mechanical stop they are simply adapteddifferently to suit the embodiment of the cylinder they are used with.

Throughout the application the term “in front of” may be used, e.g. thatfluid is in front of the master cylinder piston element. By in frontof/the front is understood the end towards which the master cylinderpiston element moves when the pedal is being depressed. This front endis considered the first end of the master cylinder chamber.

As mentioned above, the cylinder chambers are separated by a wall withopenings that allow fluid to pass from the master cylinder chamber tothe slave cylinder chamber (the fluid can also pass through theseopenings from the slave cylinder chamber back into the master cylinderchamber). In one embodiment of the brake cylinder, the wall includesonly one opening which may be located both (i) next to the stop forstopping the master piston in the master cylinder chamber and (ii) nextto the stop for stopping the slave piston the slave cylinder chamber. Inthis configuration, the opening is not blocked by the pistons, and thefluid may flow freely between the master cylinder chamber and the slavecylinder chamber (thereby, improving the operation of the brakecylinder). Both the master piston and the slave piston may be configuredwith recesses or rims having reduced cross section to allow flow offluid to and from the opening.

In configurations where there is no separate stop element in the mastercylinder chamber and/or the slave cylinder chamber the one or moreopenings will similarly be located both (i) next to the end wall at thefirst end of the master cylinder chamber and (ii) next to the end wallof the first end of the slave cylinder chamber. In this configuration,the opening is not blocked by the pistons, and the fluid may flow freelybetween the master cylinder chamber and the slave cylinder chamber(thereby, improving the operation of the brake cylinder). Both themaster piston and the slave piston may be configured with recesses orrims having reduced cross section to allow flow of fluid to and from theopening.

In variants where the fluidic communication between the master cylinderchamber and the slave cylinder chamber is affected by another channelthan the one or more openings in the wall dividing the chambers, theinlet and outlet of this channel in the master cylinder chamber andslave cylinder chamber respectively is located in the same manner asdescribed for the location of one or more openings. That is to say thatthe channel inlet will be next to the master cylinder stop member or endwall at the first end of the master cylinder chamber, while the outletwill be next to the slave cylinder stop member or end wall at the firstend of the slave cylinder chamber.

In one embodiment of the brake cylinder, the slave cylinder chambercommunicates with a pressure sensor. The pressure sensor measures thepressure of the fluid in the slave cylinder chamber and converts thismeasurement into an electronic signal to be used for signaling thebraking to the simulator software.

To obtain a more realistic or natural feeling of the brake, the brakecylinder may include a dampening device, and in one embodiment, theslave piston communicates with the dampening device. In one embodiment,the dampening device is located outside the slave cylinder chamber andcommunicates with the slave piston via a slave cylinder rod. In oneembodiment, the dampening device includes a damper in a damper housingwhich cooperates with a block element connected with the slave cylinderrod. When the slave piston is activated, the block element is drawntowards the damper by the slave cylinder rod and applies pressure on thedamper. The damper is capable of deforming when pressure is applied,thereby providing a dampening effect.

In one embodiment, the damper housing is located outside the slavecylinder chamber in a manner where it is coaxially adjacent to the slavecylinder chamber.

In one embodiment, the block element has an edge or a protrusionlimiting how far the block element can move into the damper house andthereby how far the brake pedal can be pressed. The edge or protrusionforms a mechanical stop between two solid components of the brakecylinder causing a hard limit to the movement of the block element. Theedge or protrusion is also found in alternative versions of the blockelements such as the equivalent damper piston and the effect of creatinga mechanical stop against another surface of the brake cylinder is thesame.

Having a mechanical stop blocking the piston movement of the blockelement or damper piston enables the braking process to be divided intotwo phases. During the first phase of the braking process, i.e. beforethe mechanical stop is contacted, the pedal can be moved. During thesecond phase of the braking process, i.e. once the stop is contacted,the mechanical stop limits the further movement of the pedal. Indifferent embodiments the brake cylinder is configured such that thelength of the first phase can be adjusted, by adjusting the distance thepedal has to travel before the mechanical stop is contacted. This isequivalent to the feeling of a real pedal in a car where the resistancewill change during the braking process.

The benefits of two-phase braking are achieved by the presence of amechanical stop regardless of whether the master cylinder chamber andthe slave cylinder chamber of the brake cylinder are integrated orwhether they are two separate chambers connected by an external channel.

The benefits of two-phase braking are achieved by the presence of amechanical stop are achieved both in a hydraulic braking system and in apurely mechanical braking system with a single cylinder.

In alternative embodiments based on the same underlying principle, thedampening device may include a damper in a damper housing whichcooperates with a damper piston physically connected with the slavecylinder rod. When the slave piston is activated, the damper piston ispushed towards the damper by the slave cylinder rod and applies pressureon the damper. Hence, the damper piston is a specific variant of a blockelement in contact with the slave cylinder piston, which is arranged topush against the damper rather than drawing on the damper, but bothcomponents have the same effect in that they are means for transferringforce from the slave cylinder to the damper. The damper is capable ofdeforming when pressure is applied, thereby providing a dampeningeffect.

In the two-phase braking system with a damper and a mechanical stop, thedamper will provide resistance in the first phase as the pedal moves andthe resilient material of the damper is compressed. In the second phasethe damper remains compressed and the movement of the pedal is stoppedby the mechanical stop.

Throughout the application the terms damper and dampener will be usedinterchangeably to describe the damper element of the dampening device.

In one embodiment, the damper is made from an elastomer material, suchas nitril, silicone, fluorosilicone, neoprene, polyacrylate,polyurethane, polyisoprene, and similar material. In one embodiment, thedampener has a Shore A hardness in the range 30 to 90, such as in therange 40 to 80 when measured according to ASTM D2240. A hardness withinsuch ranges provides a feeling in the brake pedal similar to the feelingof a brake pedal in a vehicle.

In another variant the damper is made from a spring such as acompression spring or a disc spring.

An alternative embodiment of the braking system comprises a mechanicalbraking cylinder, which functions without the need of a fluid within thebrake cylinder. Such a mechanical brake cylinder of a mechanical brakingsystem needs only a single cylinder chamber. Such a mechanical brakechamber has a cylinder rod entering at a first end and a damper locatedat an opposite second end. In such an arrangement pressing the pedalallows movement of the cylinder rod towards the damper which is thencompressed. The mechanical brake cylinder further comprises a mechanicalstop, such that the mechanical brake cylinder provides a two-phasebraking process. The mechanical brake cylinder is a more simplifiedstructure than the brake cylinder with two chambers and can be made morecheaply.

The present invention also relates to a brake system comprising a brakecylinder as described above for gaming and simulation.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute apart of this disclosure, illustrate various embodiments and aspects ofthe present disclosure. In the drawings:

FIG. 1 illustrates a perspective view of a brake system with a brakecylinder according to an embodiment consistent with the presentdisclosure;

FIGS. 2A and 2B illustrate respectively a side view of the brakecylinder of FIG. 1 and a cross section of the brake cylinder of FIG. 1;

FIGS. 3A and 3B illustrate respectively a side view of the brake systemof FIG. 1 in a released orientation and a cross section of the brakecylinder of FIG. 1 in the released orientation; and

FIGS. 4A and 4B illustrate respectively a side view of the brake systemof FIG. 1 in a depressed orientation and a cross section of the brakecylinder of FIG. 1 in the depressed orientation; and

FIGS. 5A and 5B illustrate respectively a side view of a brake cylinderaccording to an alternative embodiment of the brake cylinder of FIG. 1in the released, default orientation and a perspective cross section ofthat embodiment of the brake cylinder; and

FIG. 6 illustrates an external view of an alternative embodiment of abrake cylinder having its damper housing on the opposite side of theattachment opening, which may replace the brake cylinder of FIG. 1 to beused with the same type of pedal; and

FIG. 7 illustrates a perspective cross section of an alternativeembodiment of a brake cylinder which may replace the brake cylinder ofFIG. 1 to be used with the same type of pedal, the cylinder is shown inthe released orientation; and

FIG. 8 illustrates a cross sectional view of an embodiment of a brakecylinder based on the same working principle as the one illustrated inFIG. 7; and

FIG. 9 illustrates an alternative embodiment of a brake cylinder whichmay replace the brake cylinder of FIG. 1 to be used with the same typeof pedal, the cylinder is mechanical having a single cylinder chamber.

FIGS. 10A and 10B illustrate an alternative embodiment of a brakecylinder which may replace the brake cylinder of FIG. 1 to be used withthe same type of pedal, the cylinder is mechanical having a singlecylinder chamber; and

FIGS. 11A and 11B illustrate embodiments of a two-phase mechanical brakecylinder based on the same principle described in FIG. 9; and

FIGS. 12A and 12B illustrate embodiments of a two-phase mechanical brakecylinder based on the same principle as the embodiment described inFIGS. 10A and 10B; and

FIGS. 13A and 13B conceptually depicts the general concept of themechanical stop, piston and dampening device according to oneembodiment.

DETAILED DESCRIPTION

The following detailed description refers to the accompanying drawings.Wherever possible, the same reference numbers are used in the drawingsand in the following description to refer to the same or similar parts.While several exemplary embodiments and features of the disclosure aredescribed herein, modifications, adaptations, and other implementationsare possible without departing from the spirit and scope of thedisclosure. For example, substitutions, additions, or modifications maybe made to the components illustrated in the drawings, and the exemplarymethods described herein may be modified by substituting, reordering, oradding steps to the disclosed methods. Accordingly, the followingdetailed description does not limit the disclosure. Instead, the properscope of the disclosure is defined by the appended claims.

Systems and devices consistent with the present disclosure generallyrelate to a brake cylinder. More particularly, systems and devicesconsistent with the disclosure relate to a brake cylinder for use inautomotive simulators that is both cost effective to produce andprovides authentic feedback when in use.

FIG. 1 illustrates an embodiment of brake system for use in anautomotive simulation system such as a racing video game simulator or aprofessional racecar driver training simulator. The brake systemincludes a brake pedal 101 connected to a brake cylinder 201. The brakepedal 101 and brake cylinder 201 are mounted to a base or supportsurface 103. In some embodiments, the brake pedal 101 is mounted via apivot axis 105 on the base 103 having a large surface area and weight toensure that the brake system is supported in a stable manner.

The brake system is configured to communicate with a computer systemrunning car simulation software. Communication between the brake systemand the computer system could be via wires such as USB or via wirelesscommunication such as Bluetooth. The communication between the brakesystem and the computer system may be in real-time to ensure that anyactions on the brake pedal are immediately communicated to the carsimulation software to minimize lag time and provide a realistic feelfor the user using the simulation software. When pressing the brakepedal 101, a master cylinder piston 107 is pushed into the brakecylinder 201 and the brake pressure is then measured and communicatedback to the computer system via the sensor 109. The sensor 109 is ableto detect when, how much, and how fast pressure on the brake pedal ischanged. The brake cylinder 201 is connected to the brake pedal 101 by arod clevis 207 at the end of the piston rod 205 of the master cylinderpiston 107 which grips around a mount plate 113 on the arm of the brakepedal 101.

A rod clevis 207 is a specific example embodiment of a brake cylinderconnector, and the two terms will be used interchangeably and uses thesame reference number 207.

FIGS. 2A and 2B illustrate external and internal components of the brakecylinder 201. As seen in FIG. 2A, the brake cylinder 201 includes abrake cylinder housing 203 and an attachment opening 202 which can beused for mounting the brake cylinder 201 to a support system of thebrake system such as the base 103. Further, at the top of the brakecylinder 201, a pressure sensor 204 is mounted for measuring pressurewithin the brake cylinder 201 and converting a pressure measurement intoan electronic signal that can be sent to a processor of the automotivesimulation system and be interpreted using the simulator software run onthe processor to indicate the amount braking that should be applied to avehicle simulated by the automotive simulation system (the electronicsignal could be communicated either wireless or via wires).

As seen in FIG. 2A, attached through a lower part of the brake cylinderhousing 203, a master cylinder piston 107 includes a master cylinder rod205, a brake pedal connector 207, and a brake arm adjuster 209. Thebrake cylinder 201 is connected to the brake pedal 101 via the brakepedal connector 207 which may be in the form of, for example, a rodclevis. The brake arm adjuster 209 may be used for adjusting the slackin the pedal by increasing or decreasing the distance between the rod205 and the connector 207 and for adjusting the position of the pedal101 when not being pressed. The brake arm adjuster 209 can be used foradjusting the length of the master cylinder rod 205 by screwing thewinding 210 at the end of the rod 205 either into or out of the winding210 at the inner part of the rod clevis 207. When depressing the pedal101 (as seen in FIG. 1) connected to the master cylinder rod 205 via theadjuster 209 and the connector 207, the master cylinder piston 107 ispushed into the brake cylinder housing 203 increasing the internalpressure of the brake cylinder 201.

It is the pressure increase in internal pressure caused by thedepression of the pedal 101 which may be detected by a pressure sensor204.

As seen in FIG. 2B, a master cylinder rod guide 211 is mounted insidethe housing 203 for guiding the master cylinder rod 205 of the mastercylinder piston 107 and allowing movement of the rod 205 only in anaxial direction. The end of the master cylinder rod 205 disposed withinthe housing 203 includes a piston element 213 with a seal 242. Thepiston element 213 can move back and forth inside a master cylinderchamber 215 where a fluid (e.g., oil or other liquid) is present. Themovement of the master cylinder piston element 213 is limited by the rodguide 211 and the stop member 240 at the opposite end of the mastercylinder housing 203. The stop member 240 is to ensure that fluid cannotenter from the slave cylinder chamber 221 and behind the piston element213. The stop member 240 should therefore have a length ensuring thatthe master piston 107 cannot be pressed to pass the openings 219 betweenmaster and slave chambers 215, 211. A master cylinder spring 217 is alsopresent (where one end is inserted into a hollow end of the mastercylinder rod 205 and the opposite end is inserted into the hollow stopmember 240) that, when compressed, applies pressure between the stopmember 240 and the rod 205 ensuring that the master cylinder pistonelement 213 moves back to a position associated with a releasedorientation when pressure on the pedal 101 has been released. The mastercylinder spring 217 is mounted on an internal master cylinder rod guide218 to keep the master cylinder spring 217 in place.

As seen in FIG. 2B, the cylinder 201 additionally includes a slavechamber 221. The slave chamber 221 and the master cylinder chamber 215are elongated cavities that are disposed substantially parallel to eachother and are separated from each other by a chamber dividing wall 220.One or more openings 219 are disposed within the wall 220 to allow forfluid communication between the master cylinder chamber 215 and theslave chamber 221.

When the master cylinder piston element 213 is pressed towards the fluidinside the master cylinder chamber 215 (such as in the situationdepicted in FIGS. 4A and 4B), then the fluid in the chamber 215 isforced through the one or more openings 219 in the wall 220 between thetwo chambers 215, 221 and into the slave cylinder chamber 221. Fluidentering the chamber 221 via the one or more openings 219 increases thepressure within the chamber 221 and pushes a slave cylinder pistonelement 223 connected to a slave piston rod 230 in a direction oppositethat of the master cylinder piston element 213. The dimensioning andnumber of openings 219 should be considered to ensure a sufficient flowbetween the two chambers 215, 221 when fluid is pressed from the masterchamber 215 to the slave chamber 221. If the passage between the twochambers 215, 221 is too small, then a high-pressure force is necessaryto press fluid from the master chamber 215 to slave chamber 221. In oneembodiment two openings 219 each having a diameter of around 1.5 mm maybe used, but these openings 219 may be larger or smaller depending onthe viscosity of the fluid.

The piston seal 242, 244 for each of the master cylinder piston element213 and the slave cylinder piston element 223 may be a u gasket. Whenfluid is being pressed, the lips of the u gaskets 242, 244 are pressedtowards the inner walls of the cylinder chambers 215, 221. As can beseen, the u gasket 244 of the slave piston element 223 is mountedopposite the u gasket 242 of the master piston element 213, since in themaster cylinder chamber 215 the fluid is in front of the piston element213, whereas in the slave cylinder chamber 221 fluid is between theslave piston element 223 and the slave rod guide 231. Due to the ugaskets' 242, 244 seal, air is present in the master chamber 215 behindthe master cylinder piston 107 and in front of the slave cylinder piston223. In the slave chamber 221, a hole should be present at the end toensure air is allowed to leave and enter the chamber 221 as the slavepiston 223 moves back and forth.

The end of the slave piston rod 230 distal to the master cylinder piston107 is connected to an end bolt 226 and a block element 225 via windingsat the end of the slave cylinder rod 230. When the slave cylinder piston223 is pushed by the fluid entering the slave cylinder chamber 221, theblock element 225 is dragged towards and into a brake cylinder damperhousing 227 and moves with the piston 223 back and forth based onpressure provided by the fluid entering the slave cylinder chamber 221.Inside the damper housing 227, a dampener 229 is positioned between theblock element 225 and an inner wall of the housing 227. The dampener 229is made from flexible, elastic material (e.g., rubber, silicone, etc.),where the flexibility of the elastic material influences the perceivedsoftness of the pedal 101 in use. For example, a dampener 229 withgreater flexibility will result in the pedal 101 being perceived assofter than when a stiffer dampener 229 with less flexibility is used.Additionally, a threaded nut may be included on the slave piston 223next to the block element 225 on the opposite side of the dampener 229.Manipulation of the threaded nut may be used to adjust the stiffness ofthe brake pedal 101. The block element 225 has an edge limiting how farthe block element can move into the damper house and thereby how far thebrake pedal can be pressed.

By the optional threaded nut being placed next to the block element 225on the opposite side of the dampener 229 is understood that the blockelement 225 is arranged between the threaded nut 226 and the dampener229. This threaded nut 226 is also called the end bolt 226. Thearrangement of the end bolt 226 affects the default position of theblock element 225 as screwing the bolt further onto the windings of theslave cylinder rod 230 such that the end bolt 226 is closer to thedampener 229 forces the end block 225 placed between the end bolt 226and the dampener 229 towards the dampener 229. By changing the distancebetween the block element 225 and the damper housing, the travel rangeof the pedal in the first phase of the braking process is adjusted. Thetravel range is how far the pedal can be pressed before the mechanicalstop 260 between the extending edge of the block element 225 and thedamper housing 227 is engaged such that the further movement of theblock element 225 is hindered whereafter the second phase of the brakingprocess begins. During the movement of the block element 225 thedampener 229 is being deformed and the user needs to apply force to thebrake pedal 101 to cause this deformation, this will give the user afeeling of resistance in the pedal. Once the edge of the block elementis in contact with the damper housing 227 the resistance is no longercaused by the deformation of the dampener 229, but will be the hydraulicpressure related to compression of the fluid in the brake cylinder 201.Hence, the arrangement which allows the block element 225 to travel adistance before contacting the damper housing 227 gives the user a morerealistic brake feel with two stages having significantly differentresistance, i.e. requiring significantly different force to be appliedby the user to the pedal. In the second phase the user will not feel thepedal move even as the pressure rises and detects increased brakingforce.

In the slave cylinder chamber 221, a slave rod guide 231 is mountedinside the housing 203 for guiding the rod of the slave piston 223 andallowing movement of the piston 223 in only the axial direction. Theslave cylinder piston 223 can move back and forth inside the slavecylinder chamber 221 where the fluid (e.g., oil or other liquid) ispresent.

A slave cylinder spring 233 is also present that, when compressed,applies pressure between an inner wall of the chamber 221 and the piston223 ensuring that the slave cylinder piston 223 moves back to a positionassociated with the released orientation when pressure on the pedal 101has been released. The slave cylinder spring 233 is mounted on theinternal slave cylinder rod guide 234 to keep the slave cylinder spring233 in place.

As seen in FIGS. 2A and 2B, the pressure sensor 204 is connected to andis in fluid connection with the chamber 221 and is configured to measurethe pressure in the chamber 221 between the slave cylinder piston 223and the slave rod guide 231.

In other embodiments the pressure sensor 204 may be arranged to be influid connection with either the slave cylinder chamber 221 or themaster cylinder chamber 215 at any position along the cylinder housing203. In yet other embodiments the pressure sensor 204 mare be arrangedspaced away from the cylinder housing 203 while still being in fluidconnection with either the master cylinder chamber 215 or the slavecylinder chamber 221, e.g. by connection with a tube.

FIGS. 3A and 3B illustrates the brake system in the releasedorientation, where the pedal 101 is not pressed. As seen in FIG. 3A, thepedal 101 is connected to the master piston rod 205 but there is nopressure on the pedal 101. Consequently, since no pressure is applied tothe master piston rod 205 from the pedal 101, the fluid remains in themaster cylinder chamber 215 and does not pass through the holes 219 andinto the slave cylinder chamber 221. Accordingly, since no fluid isadded to the chamber 221 from the chamber 215, the pressure sensor 204measures no increased level of pressure. Because the pressure sensor 204does not measure an increased level of pressure in the chamber 221, theprocessor of the automotive simulation system does not receive anysignal indicative of braking.

FIGS. 4A and 4B illustrates the brake system in a depressed orientation,where the pedal 101 is pressed.

As seen in FIG. 3A, the pedal 101 is connected to the master cylinderpiston rod 205 and there is pressure on the pedal 101 (illustrated byblack arrow). Consequently, since pressure is applied to the masterpiston rod 205 from the pedal 101, the fluid is pushed from the mastercylinder chamber 215, through the holes 219, and into the slave cylinderchamber 221. Accordingly, since fluid has been added to the chamber 221from the chamber 215, the slave cylinder piston 223 is pushed and anincreased pressure of fluid in the area 221 in front of the slavecylinder piston 223 is measured by the pressure sensor 204. By means ofthe slave cylinder rod 230, when the slave piston 223 is pushed, itdrags the block element 225 into the damper housing 227 and appliescompressive pressure onto the dampener 229. The increased pressurecauses the dampener 229 to deform which affects the movement of theslave cylinder piston 223 which again affects the entire brake systemproviding a feeling corresponding the feeling of a brake system in avehicle. The deformation of the dampener 229 is an elastic deformation,and when the pressure is released, the dampener will regain its initialshape (i.e., the shape of the dampener 229 in an unloaded condition).Further the pedal 101 can be pushed no further due to the edge of theblock element 225 being blocked by the edge of the damper housing 227.The resistance of the dampener 229 is felt by a user's foot on the pedal101 and provides a tactile feedback similar to a brake of a real car.Because the pressure sensor 204 does measure an increased level ofpressure in the chamber 221, the processor of the automotive simulationsystem receives a signal from the sensor 204 indicative of braking.Because the amount of increased pressure measured by the sensor 204 canvary with the amount of pressure applied by a user's foot on the pedal101, the signal from the sensor will be indicative of the amount ofbraking that a user is applying to the pedal 101.

The principle described can be equivalently employed in a braking systemwherein the master cylinder chamber 215 and the slave cylinder chamber221 are physically separated, i.e. not built into the same cylinderhousing 203. In such embodiments the master cylinder chamber 215 and theslave cylinder chamber 221 are connected by an external channel ratherthan a hole in a shared wall as they do not need to share a wall. Theworking principle of exchange of fluid between the chambers 215,221 andthe movement of the cylinder rods 205,230 remains the same as will beapparent to one skilled in the art.

FIGS. 5A and 5B illustrates an alternative embodiment of the brakecylinder 201. In FIG. 5A shown from the outside and in FIG. 5B shown inschematic cross-sectional view. The working principle is the same as inthe previously described embodiments, the FIGS. 5A and 5B simplyillustrate alternative arrangements of some of the features of the brakecylinder 201 and they may be used either in combination as in theillustration or having either separately incorporated in the previouslydescribed embodiments.

FIG. 5A illustrates a brake cylinder 201 for use with a pedal 101 of abrake system for driving simulation according to the invention. Same asfor the other example embodiments the brake cylinder 201 comprises acylinder housing 203, an attachment opening 202 for connecting the brakecylinder 201 to a support surface 103, and a master cylinder rod 205 forconnecting the brake cylinder 201 to a brake pedal 101 via a brake pedalconnector 207. In an embodiment the master cylinder rod 205 is connectedto the brake pedal connector 207 via a brake arm adjuster 209 which hasa winding allowing for the adjustment of the distance 206 between thebrake cylinder rod 205 and the brake pedal connector 207. In otherembodiments the brake cylinder rod 205 and brake pedal connector 207 maybe connected by other means such as but not limited to the mastercylinder rod 205 and the brake pedal connector 207 being integrated,being welded together or releasably connected through winding or beingscrewed together by a transverse screw and bolt.

In some embodiments as illustrated in FIG. 5A the brake cylinder 201 isequipped with a first external channel connecter 241 for fluidicallyconnecting a first end of an external channel (not shown) to the mastercylinder chamber 115 and a second external channel connector 242 forfluidically connecting a second end of an external channel (not shown)to the slave cylinder chamber 221. In some embodiments the externalchannel is a tube directly connecting the first 241 and second externalchannel connector 242 and enabling the exchange of fluid between themaster cylinder chamber 215 and the slave cylinder chamber 221. In someembodiments an external channel connected to the first external channelconnector 241 and the second external channel connector 242 replaces theone or more holes 219 while serving the same purpose of enabling fluidexchange between the chambers 215,221 when pressure is applied and themaster cylinder piston element moves. In other embodiments the brakecylinder 201 may comprise a first external channel connector 241, asecond external channel connector 242 and an external channel inaddition to one or more holes 119 in the separating wall 220 between themaster cylinder chamber 115 and the slave cylinder chamber 221. Thenumber and dimensioning of the external channel and/or the one or moreholes 119 may be adapted between different embodiments of the brakecylinder 201 to control the flowrate and resistance of the system. Insome embodiments the external channel may connect the master cylinderchamber 215 and the slave cylinder chamber 215 via one or more otherpieces of equipment such as but not limited to diagnostics tools,pressure sensors and/or filters.

FIG. 5B illustrates an embodiment having a solid separating wall 220,separating the master cylinder chamber 15 and the slave cylinder chamber221, by solid is understood that the wall does not have one or moreholes or other breaches allowing fluid communication between thechambers 115,221 through the separating wall 220. In such an embodimentthe master cylinder chamber 215 and the slave cylinder chamber 221 arein stead in fluid communication through an external channel connected tothe chambers via external chamber connectors (not visible in thecross-sectional view). In an embodiment the first external channelconnector connects the external channel to the master cylinder chamber215, near the first end of the master cylinder chamber 215′, that isbetween the master cylinder piston element 213 and the end wall at thefirst end of the master cylinder chamber 215′. In an embodiment thesecond external channel connector connects the external channel to theslave cylinder chamber 221 near the first end of the slave cylinderchamber 221, i.e. between the slave piston element 223 and the damperhousing 227.

The embodiment illustrated in FIG. 5B further differ from the previouslyillustrated embodiments in that the master cylinder rod 205 is solid andthat the piston element 213 is releasably connected to the mastercylinder rod 205 by means of an external winding on the first end of themaster cylinder rod 205′ and an internal winding in a recess of themaster cylinder piston element 213. In an alternative embodiment themaster cylinder rod 205 may comprise a recess with internal windingwhich may connect to an external winding on a protrusion on the mastercylinder piston element 213. In yet other embodiments the mastercylinder rod 205 may be connected to the master cylinder piston element213 by other known means such as a press fit or gluing.

In some embodiments the slave cylinder piston element 223 is similarlyconnected to the slave cylinder rod 230 by the second end of the slavecylinder rod 230″ extending into a hollow of the slave cylinder pistonelement 223. In some variants the slave cylinder rod 230 will further beconnected to the slave cylinder piston by a winding or by other knownmeans of connection.

In some embodiment as illustrated in FIG. 5B a master cylinder spring217 is arranged between the first end of the master cylinder chamber115′ and the master cylinder piston element 213. In an embodiment thefirst end of the master cylinder spring 217′ is arranged to contact andbe guided by a master cylinder stop member 240 arranged at the first endof the master cylinder chamber 215′. The master cylinder spring 217 maybe guided by the master cylinder stop member 240 by being arranged suchthat at least part of the first end of the master cylinder spring 217′encircles the master cylinder stop member 240, in such an embodiment themaster cylinder stop member 240 may be solid. Alternatively the mastercylinder spring 217 may be guided by the master cylinder stop member 240by having at least part of the first end of the master cylinder spring217′ arranged inside a hollow of the master cylinder stop member 204.The second end of the master cylinder spring 217″ is arranged to contactthe master cylinder piston element 213. In a variant at least part ofthe second end of the master cylinder spring 217″ is arranged toencircle at least part of the master cylinder piston element 213 suchthat the master cylinder piston element 213 may act as a guide for themaster cylinder spring 217. By something acting as a guide for a springis understood that it limits the movement of the spring, such that theend of the spring does not significantly change position in thedirection perpendicular to the axis of the chamber in which the springis arranged.

In alternative embodiments wherein there is no master cylinder stopmember, the first end of the master cylinder spring 217 is arranged tocontact the end wall at the first end of the master cylinder chamber217′. In such cases the first end of the master cylinder spring 217′ maybe mounted in or otherwise connected to the end wall at the first end ofthe master cylinder chamber 217′.

In some embodiments the slave cylinder spring 233 may similarly bemounted between the slave cylinder piston element 223 and the end wallat the second end of the slave cylinder chamber 221″ or a slave cylinderstop element 245 mounted at said end wall. In an embodiment the slavecylinder spring 233 is mounted such that the first end of the slavecylinder spring 233′ is guided by the slave cylinder piston element 223,e.g. by at least part of the first end of the slave cylinder spring 233′encircling at least part of the slave cylinder piston element 223. In anembodiment the second end of the slave cylinder spring element 221″ isguided by a slave cylinder stop element 245, e.g. by at least a part ofthe second end of the slave cylinder spring element 221″ being arrangedto encircle at least a part of the slave cylinder stop element 245. Inan alternative embodiment where there is no slave cylinder stop element245 comprised in the slave cylinder chamber 221 the second end of theslave cylinder chamber spring 233″ is mounted in or otherwise connectedto the end wall at the second end of the slave cylinder chamber 221″.

Same as for the previously described embodiments the brake cylinder 201of FIGS. 5A-5B function by the exchange of fluid between the mastercylinder chamber 215 and the slave cylinder chamber 221 and theincreased pressure within the brake cylinder 201. Hence, it isunderstood that all the elements have the same functionality, i.e. theexternal channel has the same functionality as the one or more holes inthe separating wall, the springs 217, 233 maintain the samefunctionality as does the differently mounted piston elements 213,223.Namely, when a user applies pressure to the pedal, pressure istransferred via the master cylinder rod 205 to the master cylinderpiston element 213. The master cylinder piston element 213 compressesthe master cylinder spring 217 and displaces fluid from the mastercylinder chamber 215 through an external channel and into the slavecylinder chamber 221. In the slave cylinder chamber 221 the addition ofthe displaced fluid in turn moves the slave cylinder piston element 223in direction of the second end of the slave cylinder chamber 221″compressing the slave cylinder spring 233. The slave cylinder pistonelement 223 being connected to the slave cylinder rod 230 causesmovement of the slave cylinder rod 230 which in turn moves the blockelement 225 towards the dampener 229 causing elastic deformation of thedamper 229. The action of the users applying pressure to the pedalcauses an increase of pressure within the brake cylinder 201, which canbe detected by a pressure sensor, which in turn can send a signal to theprocessing unit of a driving simulator. When the user releases thepressure on the pedal the forces of the compressed springs 215,233 willact upon the piston elements 213,223 moving them back to a defaultposition associated with released orientation of the system.

As the effects of the components remain the same and interact in thesame manner, in the various embodiment the skilled person wouldunderstand that it is possible to use these elements in combinationwithout changing the essence of the invention and should not beconstrued as limited to the particular combinations shown in theillustrations. For example the spring arrangement illustrated in theembodiment of FIG. 5B may be used in a an embodiment having one or moreholes in the separating wall 220, or either or both piston elements maybe mounted to the master cylinder rod and/or the slave cylinder rodrespectively in an embodiment having the spring mounted inside thehollow of the rod. In various embodiments the arrangement of rods,piston elements and springs are the same in both the master cylinderchamber 215 and the slave cylinder chamber 221, but in alternativevariants the arrangement may differ in the two chambers.

In the embodiments illustrated in FIGS. 1-5 the master cylinder rod 205and the slave cylinder rod 230 are arranged substantially parallel andat the same time staggered such that the slave cylinder rod 230 extendsfurther towards the front than the master cylinder rod 205 does. In sucha configuration the damper housing is arranged at the front end of thebrake cylinder 201, i.e. connected to and extending from the first endof the slave cylinder chamber 221′. Such an embodiment may be considereda pull configuration as the depression of the pedal leads to the blockelement attached to the slave cylinder rod 230 being pulled towards thedampener 229.

In this embodiment, there is described an integrated hydraulic brakecylinder, i.e., integrated master cylinder and slave cylinder, where theslave cylinder comprises a slave piston that compresses a damper bypulling a flanged nut against the end of the damper. In this embodiment,the flanged nut on the backside determines the pre-load as well as whenthe flange touch the damper housing that defines a mechanical stop.While this embodiment, is described in terms of an integrated cylinders,it is also possible that it may be configured in a non-integratedcylinder, e.g., in separate master and slave cylinders.

FIGS. 6 and 7 illustrate alternative embodiments of the brake systemwhich is based on the same working principle but arranged in a pushconfiguration, wherein depression of the brake pedal 101 and thedisplacement of fluid from the master cylinder chamber 215 to the slavecylinder chamber 221 leads to the slave cylinder rod 203 pushing theblock element towards the dampener 229. In this embodiment, there isdescribed an integrated hydraulic brake cylinder where the slavecylinder comprises a slave piston that pushes against and therebycompresses a damper. In this embodiment, inserts within the damperdetermines the mechanical stop, while a nut at the end of the damperhousing determines the pre-load. While this embodiment is described interms of an integrated cylinder, it is also possible that it may beconfigured in a non-integrated cylinder, e.g., in separate master andslave cylinders. In other words, in such a configuration the damperpiston which may be seen as equivalent to the block element ispositioned on the side of the dampener 229 facing the slave cylinderpiston element 223. In such a push configuration damper housing may bearranged at the second end of the slave cylinder chamber 221″, i.e.adjacent to the entry of the master cylinder rod 205 into the second endof the master cylinder chamber 215″. A brake cylinder 201 according tothe variant illustrated in FIGS. 6A and 6B may be used with a pedal 101in the same manner as disclosed for the previous embodiments byreplacing the brake cylinder 201 of the previous embodiment. In anembodiment of the push configuration brake cylinder 201 it comprises anattachment opening 202 for releasably connecting the brake cylinder 201to a support surface 103 such as a mount plate 113 and a brake pedalconnector 207, such as a rod clevis, for connecting the brake cylinder201 to a mount plate 113 of the brake pedal 101.

FIG. 6 is an external view of a brake cylinder housing 203 having damperhousing 227 arranged at the opposite end of the attachment opening 202.The illustrated embodiment comprises a first external channel connectorand a second external channel connector for connecting an externalchannel for bringing a master cylinder chamber and a slave cylinderchamber in fluid communication. In the embodiment illustrated in FIG. 6a pressure sensor may be connected in the external channel rather thandirectly to the cylinder housing 203. Alternatively, the pressure sensormay be connected directly to a chamber through the cylinder housing 203.It could for example be through an external connector 243 made in thehousing for that purpose. It is to be understood that while the externalconnector 243 is in FIG. 6 shown as being connected to the slavecylinder chamber, the pressure sensor is not restricted to be connectedto any particular chamber or in any particular position as the pressurein the closed hydraulic system remains the same through the system andmay be measured at any point.

FIG. 7 is a schematic illustration of the internal component of analternative embodiment of the brake cylinder 201.

As seen in FIG. 7 the brake cylinder 201 includes a brake cylinderhousing. Similar to the other embodiments the brake cylinder housingcomprises a master cylinder chamber 215 and a slave cylinder chamber221, the two chambers 215,221 each being an elongated cavity which aredisposed substantially parallel to each other. The master cylinderchamber 215 and the slave cylinder chamber 221 are separated by achamber dividing wall 220. One or more openings 219 are disposed withinthe wall 220 to allow for fluid communication between the mastercylinder chamber 215 and the slave chamber 221.

A master cylinder rod guide 211 is arranged for guiding a mastercylinder rod 205 of the master cylinder piston and allowing movement ofthe rod 205 only in an axial direction. In some variants the mastercylinder rod guide 211 may be mounted inside the master cylinder chamber215 in some other variants the master cylinder rod guide 211 may bemounted adjacent to and/or abutting the master cylinder chamber. Thefirst end of the master cylinder rod 205′ is disposed within the mastercylinder chamber 215 and contacts a piston element 213, the pistonelement 213 being equipped with a seal 242. In some variants the mastercylinder rod 205 may be connected to the piston element 213, for exampleby means of threading allowing the piston element 213 to be releasablyconnected with the master cylinder rod 205 by screwing the pistonelement 213 onto the master cylinder rod 205. In other variants themaster cylinder rod 205 may be abutting the piston element 213 and beingarranged such that they may be in contact. The piston element 213 isadapted to move back and forth inside the master cylinder chamber 215along the direction of the longitudinal axis of the master cylinderchamber 215. The master cylinder rod 205 is arranged such that themovement of the master cylinder rod affects the movement of the pistonelement 213. A stop member 240 may be located at the first end of themaster cylinder chamber 215′, i.e. the end of the master cylinderchamber 215 opposite the end at which the master cylinder rod 205 entersthe master cylinder chamber 215 which in turn is the second end of themaster cylinder chamber 215″. The movement of the master cylinder pistonelement 213 is limited by the rod guide 211 and either the stop member240 or the first end of the master cylinder chamber 215′. The rod guide211 limits the movement of the master cylinder rod 205 to be along theaxis of the master cylinder chamber 215. In embodiments having the stopmember 240, it limits how far the master cylinder piston element 213 cantravel inside the master cylinder chamber 215. In a variant the stopelement 240 is adapted to ensure that the master cylinder piston elementcannot move past the one or more openings 219 such that fluid from theslave cylinder chamber 221 cannot enter the master cylinder chamber 215behind the master cylinder piston element 213. This is achieved by thelength of the stop member 240 being such that it ensures that the mastercylinder piston element 213 cannot be extended past the opening 219between the master and the slave chambers 215, 211. In embodimentshaving no stop member 240, the distance which the master cylinder pistonelement 213 can travel is limited by the first end of the mastercylinder chamber 215′ and the dimensions of the piston element 213itself, in particular the length of the piston element 213. In othervariants of such embodiments with no stop member 240, the placement ofthe one or more openings 219 and the length of the piston element 213are such that the entirety of the master cylinder piston element 213cannot be extended past the opening 219 between the master and the slavechambers 215, 211 such that fluid cannot enter the space between thesecond end of the master cylinder chamber 215″ and the master cylinderpiston element 213.

A master cylinder spring 217 is arranged within the master cylinderchamber 215. A first end of the master cylinder spring 217′ is disposedat the first end of the master cylinder chamber 215′. In someembodiments having a stopper member 240 arranged at the first end of themaster cylinder chamber 215′ the first end of the master cylinder spring217′ may be arranged within a hollow opening of the stop member 240. Inother variants the embodiment having a stopper member 240 arranged atthe first end of the master cylinder chamber 215′ the first end of themaster cylinder spring 217′ may be arranged such that the first end ofthe master cylinder spring 217′ encircles the master cylinder stoppermember 240. In other embodiments wherein the master cylinder chamber 215comprises no stopper member the first end of the master cylinder spring217′ is at least partially arranged within a cavity in the end wall ofthe first end of the master cylinder chamber 215′. In another variantthe first end of the master cylinder spring 217′ is arranged to abut theend wall at the first end of the master cylinder chamber 215′.

In some embodiments the second end of the master cylinder spring 217″opposite of the first end of the master cylinder spring 217′ is disposedwithin a hollow opening of the master cylinder rod 205 such that atleast part of the master cylinder spring 217 extends through the body ofthe master cylinder piston element 213.

In alternative embodiments the master cylinder rod 205 is solid and thesecond end of the master cylinder spring 217″ is guided by the pistonelement 213. In such embodiments the second end of the master cylinderspring 217″ may be arranged within a hollow section of the mastercylinder piston element 213 such that at least part of the mastercylinder spring 217 is encircled by part of the master cylinder pistonelement 213. In such a configuration the second end of the mastercylinder spring 217″ may abut the first end of the master cylinder rod205′ if a central channel extends throughout the body of the pistonelement 213, such a channel may for example be equipped with internalthreading for connecting the piston element 213 to the master cylinderrod 205. In alternative variants of such embodiments the second end ofthe master cylinder spring 217″ may be disposed to surround part of themaster cylinder piston element 213. In these configurations, the mastercylinder piston element 213 guides the second end of the master cylinderspring 217″ by restricting its movement in the radial direction withinthe master cylinder chamber 215, that is in any other direction than theaxial direction of the master cylinder chamber 215.

When force is applied to the master cylinder rod 205, i.e. when a userapplies pressure to the pedal, such that the master cylinder rod 205moves further into the master cylinder chamber 215, i.e. in thedirection from the second end of the master cylinder chamber 215″towards the first end of the master cylinder chamber 215′, the mastercylinder spring 217 is compressed. The forces of the compressed mastercylinder spring 217 applies force to the points of contact at the first217′ and second end of the master cylinder spring 217″. At the first endof the master cylinder spring 217′ pressure is applied to the contactpoint at the end of the master cylinder chamber 215′, i.e. the stopmember 240 or the end wall at the first end of the master cylinderchamber 215′. At the second end of the master cylinder spring 217″pressure is applied to the contact point at the master cylinder rod 205and/or the master cylinder piston element 213 such that the spring forceis applied to the master cylinder rod 205 either directly or transmittedto the master cylinder rod 205 via the master cylinder piston element213.

The force from the master cylinder spring 217 acts upon the mastercylinder rod 205 to move it back to a position associated with a defaultposition of the master cylinder rod 205 associated with no pressurebeing applied by a user to the pedal 101. In other words, by the defaultposition is understood the unloaded position of the brake and brakecylinder.

In some embodiment the master cylinder spring 217 may be mounted aroundan internal master cylinder rod guide 218 to keep the master cylinderspring 217 arranged as intended. In other embodiments the mastercylinder spring 217 will be guided to stay in the intended position bythe master cylinder piston element 213 and/or the master cylinder stopmember 240 and/or a cavity in the end wall of the first end of themaster cylinder chamber 217′.

Similar to the configuration in the master cylinder chamber 215, theslave cylinder chamber 221 comprises a slave cylinder rod guide 231mounted inside the slave cylinder chamber 221 for guiding a slavecylinder rod 230 and allowing movement of the slave cylinder rod 230only in an axial direction substantially parallel to the axis ofmovement of the master cylinder rod 205. At least part of the slavecylinder rod 230 is disposed within the slave cylinder chamber 221. Theslave cylinder rod 230 is arranged such that the first end of the slavecylinder rod 230′ contacts a slave cylinder piston element 223. In someembodiments the slave cylinder rod 230 may comprise an integrated slavecylinder piston element 223 at the first end of the slave cylinder rod230′. In other embodiments the first end of the slave cylinder rod 230′may be releasably connected to the slave cylinder piston element 223 forexample by both components comprising threading such that they may bereleasably connected by screwing the slave cylinder piston element 223onto the first end of the slave cylinder rod 230′. In yet otheralternative embodiments the slave cylinder rod 230 is arranged such thatthe first end of the slave cylinder rod 230′ abuts and is in contactwith the slave cylinder piston element 223. The slave cylinder pistonelement 223 has a slave cylinder seal 244 arranged around the body ofthe slave cylinder piston element 223 to create a fluid tight sealbetween the volumes of the slave cylinder chamber separated by thecylinder piston element 223. The slave cylinder piston element 223 isadapted to move back and forth inside the slave cylinder chamber 221along the direction of the longitudinal axis of the slave cylinderchamber 221. A slave cylinder stop member 245 may be located at theclosed first end of the slave cylinder chamber 221′. Alternatively, theslave cylinder piston may stop against the end wall of the first end ofthe slave cylinder chamber 221′. The movement of the slave cylinderpiston element 223 within the slave cylinder chamber 221 along the axisof the slave cylinder chamber 221 is at the second end of the slavecylinder chamber 221″ limited by the rod guide 231 and at the first endof the slave cylinder chamber 221′ it is limited either by the slavecylinder stop member 245 or alternatively by the end of the slavecylinder chamber. The slave cylinder rod guide 231 optionally incombination with slave cylinder spring 233 limits the movement of theslave cylinder rod 230 to be along the axis of the slave cylinderchamber 221.

In various embodiments the slave cylinder piston element 223 is arrangedsuch that it cannot translate past the one or more openings 219 suchthat fluid from the master cylinder chamber 215 cannot enter the slavecylinder chamber 221 behind the slave cylinder piston element 223, i.e.on the side of the slave cylinder piston element 223 closest to thesecond end of the slave cylinder chamber 221″. In embodiment comprisinga slave cylinder stop element 245, this is achieved by the length of theslave cylinder stop member 245 and the dimensions of the slave cylinderpiston element 223 being such that it ensures that the slave cylinderpiston element 223 cannot be extended past the opening 219 between themaster and the slave chambers 215, 211. In embodiments where the travelrange of the slave cylinder piston element 223 is limited by the endwall at the first end of the slave cylinder chamber 221′, it is achievedby the dimensions, in particular the length of the slave cylinder pistonelement 223 along the axis of the slave cylinder chamber, being adaptedto cover all one or more holes 219 when the slave cylinder pistonelement 223 contacts the end wall at the first end of the slave cylinderchamber 221′.

In some variants of embodiments having both a master and a slave stopmembers 240,245, the dimensions of the master and the slave stop members240,245 as well as the dimensions of the master and the slave pistonelement 213, 223 are the same. In other variants the dimensions of thecomponents of the master cylinder chamber 215 and the slave cylinderchamber 221 may however vary. In yet other variants a stop member240,245 may be present in either the master cylinder chamber 215 or theslave cylinder chamber 221 while there is no stop member 240,245 in theother chamber 215,221.

A slave cylinder spring 233 is arranged within the slave cylinderchamber 221 such that the spring forces of the slave cylinder spring 233acts upon the slave cylinder piston element 223 to bring it back to adefault position corresponding to no pressure being applied by the user.In one embodiment the first end of the slave cylinder spring 233′ isarranged to contact the end of the slave cylinder piston element 223facing the second end of the slave cylinder chamber 221′ and the secondend of the slave cylinder spring 233 opposite of the first end isdisposed at the slave cylinder rod guide 231.

When force is applied to the slave cylinder rod 230 such that the slavecylinder rod 230 translates in the direction from the first end of theslave cylinder chamber 221′ towards the second end of the slave cylinderchamber 221, i.e. by a user applying pressure to the pedal, the slavecylinder spring 230 is compressed. The forces of the compressed slavecylinder spring 233 applies force to the slave cylinder piston element223 and the slave cylinder rod guide 231 such that the slave cylinderrod 230 moves back to a default position of the slave cylinder rod 230associated with no pressure being applied by a user to the pedal 101. Inan embodiment the slave cylinder spring 230 is mounted around aninternal slave cylinder rod to keep the slave cylinder spring 233 inplace.

The second end of the slave cylinder rod 230″, i.e. the end opposite theend arranged to contact the slave cylinder piston element 223, isarranged in contact with a damper piston 250. In some variants thedamper piston 250 may be connected to the slave cylinder rod 230, e.g.they may be comprised of a single piece of material or they may beassembled from two component that are fixed together or releasablyconnected. In other variants the slave cylinder rod 230 may simply bearranged to be capable of physically contacting the damper piston 250without the two components being connected such that force may betransferred from the slave cylinder rod to the damper piston 250.

A damper housing cap 224 is mounted at the second end of the slavecylinder 221″. In an embodiment the damper housing cap 224 has aninternal thread such the that the cap can apply an adjustable andvariably mechanical pressure on the damper 229. The adjustable positionof the cap may further contribute to adjusting the travel range of thepedal in the first phase of the braking process before the mechanicalstop 260 is engaged. The end bolt 226 locks the cylinder cap 224 inplace once it is in the desired position.

Equivalent to the previously described embodiments the region of theslave cylinder from the damper housing cap 224 to the damper piston 250may be considered the damper housing. The chamber within the damperhousing wherein the damper piston 250 is located may in some variants bewider than the slave cylinder chamber 221. Hence it is to be understoodthat the damper housing 227 may be considered to include the damper cap224 and/or the damper bracket 251.

In a variant a damper 229 is located between the damper piston 250 and adamper bracket 251. In different variants the one or more dampeners 229are hollow cylinder-shaped elongated pieces of resilient material thatare dimensioned such that when the system is in the relaxed defaultposition the uncompressed dampener 229 extend from the damper piston 250to the slave cylinder bracket 251. In other variants the one or moredampeners 229 may be a solid elongated piece of resilient material. Insuch variants having one or more solid dampers 229, each solid damper229 may have a depression in either or both ends for engaging part ofthe damper piston 250 and/or damper bracket 251. In embodiments with asingle solid dampener 229, the dampener may be mounted such that aflange of the damper piston 250 extends around a first end of thedampener 229 and a flange of the damper bracket extends around thesecond end of the dampener 229, such that when the dampener 229 issufficiently compressed the flanges will come in mechanical contact andform a stop enabling the two-phase braking process. The resilientmaterial of the dampener 229 may for example be rubber, silicone orsimilar known materials that are flexible and elastic. The resilientproperties of the material, i.e. the force required to deform a dampener229, influences the perceived softness of the pedal 101 in use. The lessforce is required to deform and/or compress the dampener 229 the softerthe pedal 101 will be perceived by the user as less force will berequired for a response. By the one or more dampeners 229 beingelongated is to be understood that in such variants they are longer inthe axial direction of the slave cylinder chamber 221 than they are widein the transverse direction. In an embodiment such an elongated dampener229 is cylinder-shaped. In an embodiment such an elongated dampener 220is hollow which is a cylinder-shaped hollow opening in a cylinder-shapedresilient material, i.e. it is a resilient sidewall of a cylinder shape.

In an embodiment the shape of the damper piston 250 is such that aprotrusion extends at least partially into the hollow opening of thecylinder-shaped dampener, thereby fixating and guiding the direction inwhich the damper 229 is bend it is deformed under pressure from thedamper piston 250. In some variants the damper piston 250 may furthercomprise outer edges extending partially along the length of the of thedampener 229 for further fixating and controlling the dampener position.Furthermore, the protrusion of the damper piston 250 may in someembodiments serve as a mechanical stop 260, limiting the travel range ofthe pedal 101 as well as limiting the compression of the damper 229 asthe damper piston 250 can travel no further than to where the protrusioncontacts the damper bracket 251 or the damper housing cap 224. A damperbracket 251 is a part of the damper housing placed between the damper229 and the damper housing cap 224. The shape of the damper bracket 251is in an embodiment such that a protrusion extends at least partiallyinto the hollow opening of the cylinder-shaped dampener 229, therebyfixating and guiding the direction in the dampener 229 is bend it isdeformed under pressure from the damper piston 250. In some variants thedamper bracket 251 may further or alternatively comprise outer edgesextending partially along the length of the of the dampener 229 forfixating and controlling the dampener position. Furthermore, theprotrusion of the damper bracket 251 may in some embodiments serve as amechanical stop 260 as it becomes the part against which the mechanicalstop 260 of the block or damper piston 250 engages limiting the travelof the pedal 101 as well as limiting the compression of the damper 229.In an embodiment damper piston 250 and damper bracket 251 are identicalparts arranged with mirrored orientation.

The protrusion of the damper piston 250 optionally in combination with aprotrusion of the damper bracket 251 or of the damper housing cap 224provides a mechanical stop 260 which limits the travel range of thedamper piston 250. Due to this limitation of the travel range of thedamper piston 250 the user may experience two phases with differentresistance when pressing the brake pedal. The first braking phase isexperienced when the damper piston 250 is translating under the force ofthe pedal depression and the resistance is due to the deformation of thedampener 229. The second braking phase is experienced if the usercontinues to apply pressure after the protrusion of the damper piston250 is in mechanical contact with the damper bracket 251, in this casethe resistance the user will feel is due to the hydraulic pressurewithin the brake cylinder, that is from compressing the fluid within thebrake cylinder system.

In an alternative embodiment the damper bracket 251 and the damperhousing cap 224 is an integral part as shown in FIG. 7.

In embodiments having multiple dampers 229 the damper piston 250 mayhave multiple protrusions for engaging the hollows of each damper 229.In such embodiments the damper piston 250 may further compriseprotrusions extending between neighbouring dampers to further guidetheir bending during compression. Protrusions extending betweenneighbouring dampers 229 may also be present in embodiments where one ormore dampers are made from a solid piece of resilient material, i.e.without a hollow extending through the damper.

During operation of the brake cylinder 201, applying pressure to thepedal 101 will lead to the master cylinder rod 205 being moved from itsdefault position and translating further into the master cylinderchamber 215 towards the first end of the master cylinder chamber 215′.This movement of the master cylinder rod 205 leads to the mastercylinder piston element 213 also translating in the direction towardsthe first end of the master cylinder 115′, thereby exerting a force on afluid inside the master cylinder chamber 215 (similar to the situationdescribed for the former embodiment and illustrated in FIGS. 4A and 4B).This movement of the master cylinder piston element 213 will force atleast some of the fluid from the master cylinder chamber 215 through theone or more openings 219 into the slave cylinder chamber 221. Fluidentering the slave cylinder chamber 221 via the one or more openings 219increases the pressure within the slave cylinder chamber 221 and exertsa force on the slave cylinder piston element 223 forcing it in adirection opposite that of the master cylinder piston element 213. Bythe slave cylinder piston element 223 moving in a direction oppositethat of the master cylinder piston element 213 is understood that itmoves along an axis parallel to the axis of movement substantiallyparallel to the axis of movement of the master cylinder piston element213 but towards the opposite end of said axis than the end which themaster cylinder piston element 213 moves towards, i.e. in the directionfrom the first end of the slave cylinder chamber 221′ towards the secondend of the slave cylinder chamber 221″. The dimensions of the one ormore openings 219 as well as the number of openings present 219 isadapted to control the flow of fluid exchange between the mastercylinder chamber 215 and the slave fluid chamber 221 and thereby affectthe force which must be applied to the master cylinder rod 205 to causethe slave cylinder piston element 223 to move, hence the dimensioningand number of openings 219 may vary between different embodiments of theinvention. It may be necessary to adapt the dimensioning and number ofopenings 219 depending on the fluid used, e.g. depending on theviscosity of that fluid.

In one exemplary embodiment there may be two openings 219 each having adiameter of around 1.5 mm.

While the previously described embodiments have referred to one or moreopenings 219 in the wall 220 separating the master cylinder chamber 215and the slave cylinder chamber 221, in other embodiments the fluidicexchange between the master cylinder chamber 215 and the slave cylinderchamber 221 may be through a differently arranged channel. For example,the fluidic connection may be through a tube connecting the mastercylinder chamber 215 and the slave cylinder chamber 221 externally ofthe brake cylinder 201. Such a configuration may be beneficial as itallows inspection of the fluid, e.g. through a transparent tube. Thetube may also be connected through another device allowing treatment oraffecting of the fluid. Furthermore, it enables exchanging of the tube,e.g. to change its length or in case the tube is damaged or clogged. Inyet another alternative embodiment the master cylinder chamber 215 andthe slave cylinder chamber 221 may be fluidically connected though achannel arranged in the outer wall of the brake cylinder rather than inthe wall 220 separating the chambers 215,221. Hence, the holes 219should be interpreted as a specific embodiment of any type of channelarranged to fluidically connect the master cylinder chamber 215 and theslave cylinder chamber 221.

When the slave chamber piston element 223 is forced to move, ittransfers force to the damper piston 250 which in turn is pressed in thesame direction as the slave chamber piston element 223 moves, i.e.towards the dampener 229, the damper bracket 251 and the damper housingcap 224. This movement will lead to the compression and/or deformationof the dampener 229. The amount of force needed to elastically deformthe dampener 229 depends on the material of choice of the dampener andmay vary between embodiments to allow for different load of differentbrake cylinders to match user preference.

Simultaneously with the movement of the components of the brake cylinder201 pressure is increased within the master cylinder chamber 215 and theslave cylinder chamber 221.

A pressure sensor 204 may be connected to and in fluid communicationwith the slave cylinder chamber 221 or the master cylinder chamber 215.There may be further openings in the cylinder chambers for fluidcommunication of other devices. The pressure sensor 204 is configured tomeasure the pressure in the brake cylinder 201. The pressure readingfrom the pressure sensor 204 may then be transmitted to the simulatorand correlated to a braking force within the simulation. In the defaultposition corresponding to no pressure being applied to the pedal (suchas in the configuration shown on FIG. 3A) there is no elevation of thepressure detected by the pressure sensor 204 and thus the processor ofthe automotive simulation system does not receive signal indicative ofbraking activity.

Upon release of the pedal, i.e. when the user no longer applies pressureto the pedal, the brake cylinder system will return to its defaultposition under the spring forces of the master cylinder spring 217, theslave cylinder spring 233, and the dampener 229 as the dampener 229 isdecompressed, these forces move the slave chamber piston element 223 andthe master cylinder piston element 213 back to their default positionthereby also moving fluid which had been forced into the slave cylinderchamber 221 back into the master cylinder chamber 215.

Same as for the pull configuration, the push configuration asexemplified in FIGS. 6-7, the principle can be equivalently employed ina braking system wherein the master cylinder chamber 215 and the slavecylinder chamber 221 are physically separated, i.e. not built into thesame cylinder housing 203. In such embodiments the master cylinderchamber 215 and the slave cylinder chamber 221 are connected by anexternal channel rather than a hole in a shared wall as they do not needto share a wall. The working principle of exchange of fluid between thechambers 215,221 and the movement of the cylinder rods 205,230 remainsthe same as will be apparent to one skilled in the art.

FIG. 8 illustrates a cross sectional view of an embodiment of a brakecylinder in the push configuration. The working principle and componentsof the brake cylinder 201 of FIG. 8 is the same as previously described.The embodiment shows how various features previously described may becombined.

The shown embodiment of the push configuration comprises a mastercylinder spring 217 arranged between the master piston element 213 and amaster cylinder stop element 240 arranged at the first end of the mastercylinder chamber 215′. Similarly a slave cylinder spring 233 is arrangedbetween the slave cylinder piston element 233 and a slave cylinder rodguide 231. Both springs 217,233 are arranged to bias the system towardsits default position.

The brake cylinder 201 further comprises a damper housing 227 integratedin the brake cylinder housing 203 with a dampener 229 arranged within. Ablock in the form of a damper piston 250 is arranged in contact with theslave cylinder rod on one side and the damper 229 on the other. A damperhousing cap 225 is arranged at the end of the damper housing not facingthe slave cylinder chamber 221. A damper bracket 251 is arranged betweenthe damper housing cap 225 and the damper 229. In the embodiment shownin FIG. 8 both the damper piston 250 and the damper bracket 250 compriseprotrusions forming mechanical stop 260. When pressure is applied to thepedal the master cylinder moves pressurising the fluid within the brakecylinder causing the slave cylinder rod to translate within the slavecylinder chamber. The slave cylinder rod acts on the damper piston 250which in turn compresses the dampener 229. The movement of the damperpiston 250 towards the damper bracket 251 is stopped once the mechanicalstop 260 of the damper piston contacts the protrusion of the damperbracket 251.

The braking process and the feel of the pedal may be adjusted byexchanging the damper 229 using different resilient materials or springsto adjust how much force is required to compress the dampener 229.Different embodiments may further be adjusted by the length of themechanical stop 260 of the block, damper piston and/or damper bracket,which adjusts how far the pedal can be depressed before the mechanicalstop is reached.

Some embodiments of the hydraulic brake cylinder 201, while not shown inany of the illustrations, may be made without a master cylinder spring217 and/or without a slave cylinder spring 233. In such embodiments,when the pressure applied to the pedal by the user is decreased orreleased the decompression of the dampener 229 causes the brake cylinderand pedal to return to the default position. As such it is understoodthat in embodiments wherein a master cylinder spring 217 and/or withouta slave cylinder spring 233 is present the force required to depress thepedal also includes the force required to compress such springs 217,233in addition to the force required to compress the dampener 229.

FIG. 9 is a cross-sectional view of a mechanical brake cylinder 301,having a single mechanical cylinder chamber 301. In an embodiment nofluid is present in the mechanical cylinder chamber 301 and it is not ahydraulic braking system. As no fluid is present it is to be understoodthat while the mechanical brake cylinder 301 may be constructed with amechanical cylinder chamber 315 and damper housing 227 in two separateparts or alternatively the mechanical brake may be formed as a singleintegrated part in which case int may be considered solely a damperhousing 227.

A mechanical cylinder rod 305 enters the mechanical cylinder chamber 315at the first end of the mechanical cylinder chamber 315′. A mechanicalcylinder rod guide 311 is mounted inside the mechanical cylinder chamber315, near the first end of the mechanical cylinder chamber 315′. Themechanical cylinder rod guide 311 restricts the movement of themechanical cylinder rod 305 to be only in an axial direction inside themechanical cylinder chamber 305. The mechanical brake cylinder may insome embodiments further comprise a second mechanical rod guide 331arranged inside the mechanical cylinder chamber 315, at the second endof the mechanical cylinder chamber 315′. Same as for the otherembodiments the mechanical cylinder rod 305 is connected to the pedal ofthe brake system, such that when a user applies pressure to the pedal,the force is transferred to the mechanical cylinder rod 305 causing itto translate axially inside the mechanical cylinder chamber 315. Whenpressure is applied to the pedal the mechanical cylinder rod 305translates in the axial direction from the first end of the mechanicalcylinder chamber 315′ towards the second end of the mechanical cylinderchamber 315″.

The mechanical cylinder rod 305 has a second end 305″ which is situatedopposite where the mechanical cylinder rod 305 entered the mechanicalcylinder chamber 315. The second end of the mechanical cylinder rod305″, is arranged in contact with a damper piston 250. In some variantsthe damper piston 250 may be connected to the slave cylinder rod 230,e.g. they may be comprised of a single piece of material or they may beassembled from two component that are fixed together or releasablyconnected. In other variants the mechanical cylinder rod 305 may simplybe arranged to be capable of physically contacting the damper piston250, without the two components being connected, such that force may betransferred from the slave cylinder rod to the damper piston 250. Whenthe pedal of the braking system is pressed by a user the translation ofthe mechanical cylinder rod 305 transfers force to the damper piston 250causing it to also translate in the same direction as the mechanicalcylinder rod 305.

A damper housing 227 is present at the second end of the mechanicalcylinder chamber 315″. The damper housing 227 may be an extension of themechanical cylinder chamber 315 or it may be a separate part mounted tothe second end of the mechanical cylinder chamber 315. One or moredampeners 229 as described for the other embodiments of the invention ismounted inside the damper housing 227 of the mechanical brake cylinder301. A mechanical cylinder cap 324 is adapted to be mounted to the endof the damper housing 227 furthest from the first end of the mechanicalcylinder chamber 315′. In an embodiment the mechanical cylinder cap 324has an internal thread for engaging an external thread on the damperhousing 227 such the that the mechanical cylinder cap 324 can apply a anadjustable and variably mechanical pressure on the damper 229. Theadjustable position of the cap may further contribute to adjusting thetravel range of the pedal in the first phase of the braking processbefore the mechanical stop 260 is engaged. The end bold 226 locks thecylinder cap 224 in place once it is in the desired position.

In an embodiment a damper bracket 251 is present between the mechanicalcylinder cap 324 and the one or more dampeners 229. The damper bracket251 may be an integrated piece of the mechanical cylinder cap 324 or aseparate component. In an embodiment the damper bracket 251 comprises aprotrusion which extends at least partially into the hollow,throughgoing opening of a dampener 229. In other embodiments the damperpiston 250 similarly comprises a protrusion which extends at leastpartially into the hollow, throughgoing opening of a dampener 229. Whenpressure is applied to the damper piston 250 such that it moves in theaxial direction towards the damper bracket 251, the damper 229 arrangedbetween the damper position 250 and the damper bracket 251 will becompressed and/or deformed. If enough pressure is applied to the damperpiston 250 it will move towards the damper bracket 251 until theprotrusion of the damper piston contacts the protrusion of the damperbracket 251. This contact between the two protrusions forms a mechanicalstop 260 and hinders the damper piston 250 to be moved further. Therebya two-phase braking process is achieved for the mechanical system, thefirst phase being while the dampener 229 is being compressed and thesecond phase being once mechanical contact has been established betweenthe two protrusions and the damper piston 250 can be moved no further inthe direction of the damper bracket 251 whereby the pedal also cannot bepressed further. In hydraulic brake cylinders the user applying force topedal in the second phase will exert a force on the hydraulic fluidcompressing said fluid and increasing the pressure in the cylinder. Inthe mechanical cylinder the force is exerted solely on the mechanicalcontact between the two stops, in the exemplary embodiment in the formof the two protrusions.

The skilled person will understand that the mechanical stop 260 enablingthe second phase of the braking process may be achieved by othergeometries having equivalent functionality. For example a protrusion mayextend from only the damper piston 250 and the single protrusion willform a mechanical stop 260 upon contact with a flat surface of thedamper bracket 251, or a similar configuration may have a protrusiononly from the damper bracket 251. In another example the protrusions maybe arranged differently such that they do not extend into athoroughgoing channel of a dampener 229, but extend as flanges around atleast part of either one of or both of the ends of the dampener 229.

The mechanical brake cylinder may be seen as a simplified version of thepush configuration of the brake system, having only a single mechanicalcylinder chamber 315 such that a single mechanical cylinder rod 305creates direct mechanical contact from the pedal to the damper piston250 such that depressing the pedal causes the damper bracket to movetowards the dampener 229 and compressing it until a mechanical stop 260is engaged by the damper piston 250 and it can be translated no furtherin the direction towards the dampener 229. When force is no longerapplied to the pedal, the resilient character of the dampener 229 willcause the damper piston to move back towards the first end of themechanical cylinder chamber 315 to its default position.

In different embodiments of the mechanical brake cylinder, where nohydraulic fluid is present inside the mechanical cylinder chamber, thebraking power is not determined by a pressure sensor after themechanical stop 260 has been engaged. Other known measurement devices,i.e. sensors alone or in combination with other assistive measurementmeans, may be used for determining the force applied to the pedal.

In some embodiments of the mechanical brake cylinder the sensor may be aloads cell such as strain gauge or capacitive load cells. When the loadcell is in the form of a strain gauge it will measure a direct forceapplied to the load cell as a consequence of the brake pedal beingpressed, i.e. by physical contact between a component, such as a spring,moving against a part of the load cell. In some embodiments of a brakecylinder 301 according to FIG. 1 a load cell sensor may be locatedbetween the piston bracket 251 and the mechanical cylinder cap 324 (seeFIG. 11A). In other embodiments the measurement device may be a halleffect sensor which is used in combination with a magnet, the Halleffect sensor and the magnet arranged such that depression of the brakepedal causes the distance between the hall sensor and the magnet tochange. For example a magnet may be attached to a flange of the damperpiston 250 extending around at least part of the ends of the dampener229 while a Hall effect sensor 109 is attached to a flange of the damperbracket 251 extending around at least part of the ends of the dampener229 (see FIG. 11B). In such embodiments the magnet will be moved closerto the Hall effect sensor 109 when the pedal is depressed and the damperpiston 250 compresses the dampener 229 and moves towards the damperbracket 251 allowing the detection of the change of the magnetic fieldin response to depression of the pedal. In a variant with the previouslydescribed arrangement the dimensions of the flanges is such that themechanical stop 260 is engaged before the magnet is brought intophysical contact with the Hall effect sensor such that the sensor willnot be damaged by the mechanical force. In yet other embodiments thesensor 109 used in the mechanical brake cylinder may be a rotarypotentiometer. In some embodiments such a rotary potentiometer may bemounted to detect the angular movement of the pedal as it is depressed,for example by mounting the rotary potentiometer outside the brakecylinder to measure the angular movement around the pivot axis 105 (SeeFIG. 1) where the pedal 101 is connected to the base 103.

While not illustrated on FIG. 9 the cylinder housing 303 of themechanical brake cylinder 301 may comprise an attachment opening forattaching the mechanical brake cylinder 301 to a support surface of thebrake pedal system, same as the other brake cylinder embodiments.

FIGS. 10A and 10B are a cross-sectional views of a mechanical brakecylinder 301, in an embodiment where there brake cylinder comprises adamper housing 227 on its own with no cylinder chamber. In embodimentsof the invention which are purely mechanical, i.e. with no hydraulicsystem, it is not necessary to include a cylinder chamber as there is noneed for containment of a hydraulic fluid within such a chamber. Theworking principle is the same as for the embodiment illustrated in FIG.9; while FIG. 9 comprises a closed chamber this may be considered anintegrated part of the damper housing 227 of the mechanical system or inalternative embodiment of the mechanical braking cylinder a damperhousing 227 may be attached to an end of a cylinder chamber.

The embodiment exemplary illustrated in FIGS. 10A and 10B is arrangedwith the block 225 in a push configuration, such that the movement ofthe piston causes the block 225/damper piston 250 to move in an axialdirection towards the damper thereby compressing a dampener 229 andproviding a braking signal via a sensor 109. In other words when a userapplies force to the brake pedal it causes the movement of themechanical cylinder rod 305 which in turn moves the block 225 in thedirection of the dampener 229. The damper 229 is compressed under theforce of the block moving towards it, until they point where themechanical stop 260 of the block 225 limits the further movement in theaxial direction of the block. In the embodiment shown in FIGS. 10A and10B this happens as the mechanical stop 260, in the form of an extendingflange on the block 225 contacts the damper housing 227 of themechanical brake cylinder 301.

In the illustrated embodiment of the mechanical brake cylinder 301 thesensor 109 is a load cell comprising a metal plate which will bedeformed under pressure and a strain gauge which measures thatdeformation. When the pedal is depressed and the mechanical cylinder rod305 moves forward, a mechanical cylinder spring 313 arranged in a hollowof the cylinder rod 305 is pressed against the metal plate of the loadcell causing an increased force to be applied to the load cell sensor.An arrangement using a spring the force applied to the load cell issmaller than if a rigid structure such as a rod is used, this allows forthe use of load cells that are not constructed to withstand a force asgreat as what the user applies to the pedal. In other embodiments of theinvention it is not necessary to use a spring to apply force to the loadcell, other structures such as a rod may be used. For example, thevariant shown in FIGS. 10A and 10B may have a solid mechanical cylinderrod 305 without a spring arranged such that the first end of themechanical cylinder rod 305 contacts the load cell 109 and allows thetransfer of force directly to that load cell sensor 109.

In an alternative, sensor configuration might be to substitute the loadcell with a hall effect sensor by mounting a magnet at the first end ofthe mechanical cylinder rod 305′ and having a hall effect sensor mountedinstead of the metal plate of the strain gauge 109 such that the axialmovement of the mechanical cylinder rod 305 will change the magneticfield which is sensed by the hall effect sensor.

FIG. 10A shows the mechanical brake cylinder 301 in an unloadedconfiguration, i.e. the default position where no force is applied todepress the brake pedal.

FIG. 10B shows the mechanical brake cylinder 301 in the loadedconfiguration, i.e. where the brake pedal has been depressed by a user,such that the dampener 229 has been compressed and the mechanical stop260 on the block element 225 which functions as a damper piston 250,engages the cylinder housing of the mechanical brake cylinder. Theengagement between the mechanical stop 260 and the damper housing 227hinders the brake pedal from being further depressed and the dampener229 form being further compressed.

In hydraulic embodiments of the present invention, the mechanical stopenables the two-phase braking, i.e. the first phase being thecompression of the dampener 229 and the second phase ensuing afterengagement of the mechanical stop 260 whereafter the hydraulic fluidcontained in the brake cylinder 201 is compressed under action of thepiston. In the hydraulic brake system the brake action can be measuredin both phases as the pressure increases within the brake cylinder 201as detected by the pressure sensor 204. For the purely mechanicalsystem, embodiments of which are described in FIGS. 9-10, it is notpossible to detect increased force applied to the brake pedal 101 afterthe mechanical stop 260 has been engaged. The FIGS. 10-11 illustrate analternative embodiment of a mechanical stop wherein force applied to thebrake pedal can be detected in both the first phase before engagement ofthe mechanical stop 260 and in the second phase after engagement of themechanical stop 260. This is achieved by the presence of a resilientstop damper 270 arranged to be interposed between the surfaces of themechanical stop 260 which would otherwise be in contact.

FIGS. 11A and 11B show embodiments of a two-phase mechanical brakecylinder 301 based on the same principle as the embodiment described inrelation to FIG. 9. FIGS. 11A and 11B illustrate two potential optionsfor sensor solutions in the context of a mechanical brake cylinder.

The embodiment of FIG. 11A the sensor 109 is a load cell arrangedbetween the piston bracket 251 and the mechanical cylinder cap. In theillustrated embodiment the force is conveyed to the load cell via aspring, however it is to be understood that within other embodiments ofthe invention a load cell may be arranged differently and the force maybe conveyed by a spring or by another structure, such as a rigid rod ordirectly from another structure of the brake cylinder, such as thepiston bracket 251 itself.

The embodiment of FIG. 11B illustrates a potential placement of amagnetic sensor. In this embodiment a magnet 109′ is arranged on aflange of the damper piston 250 and a Hall effect sensor 109 is arrangedon the flange of the damper bracket 251. By such an arrangement a changein the magnetic field may be detected as the distance between the magnetand the Hall effect sensor changes. In an embodiment as illustrated themagnet 109′ and Hall effect sensor 109 are arranged to directly faceeach other, however it is to be understood that this is not necessary aslong as the Hall effect sensor 109 can detect a change in the magneticfield. In some variants multiple magnets may be mounted in the systemfor a stronger magnetic signal. The illustrated placement of the magnet109′ and the Hall effect sensor 109 is exemplary, both sensor 109 andone or more magnets 109′ may be arranged elsewhere on the structure aslong as their relative distance is reproducibly changed as the pedal isdepressed.

In the embodiments of FIGS. 11A and 11B, a resilient stop damper 270 isarranged to protrude from the surface a mechanical stop 260 facinganother mechanical stop 260. As illustrated in FIG. 11 the stop damper270 is protruding from the surface of the damper bracket 251, in otherembodiments the stop damper 270 may protrude from the damper piston 250instead. In some embodiments the stop damper 270 may be attached to thesurface in other embodiments it may be embedded in and protruding fromthe surface of the damper piston 250 or damper bracket, respectively.When the mechanical cylinder rod 305 translates in the direction towardsthe damper bracket 251, the damper piston 250 will also translatetowards the damper bracket 251. The resilient dampener 229 will becompressed under the mechanical force of the damper piston 250 until themechanical stop 260 is engaged. In this embodiment the mechanical stop260 is engaged when the mechanical stop surface of the damper piston 250engages the stop damper 270 protruding from the mechanical stop surfaceof the damper bracket 251.

FIGS. 12A and 12B illustrates an embodiment of a two-phase mechanicalbrake cylinder 301 based on the same principle as the embodimentdescribed in relation to FIGS. 10A-10B. In the embodiment of FIG.12A-12B, a resilient stop damper 270 is arranged interposed between theprotruding flange part of the block element 225 which forms themechanical stop 260 of the block element 225 and the damper housing 227of the mechanical brake cylinder 301. In an embodiment as illustrated inFIGS. 12A and 12B the stop damper 270 takes the form of an O-ring orwasher arranged around the block element 225 along the face of theprotruding flange element which forms the mechanical block 260 whichfaces the damper housing 227. In such an embodiment, force applied tothe mechanical cylinder rod 305 in the direction toward the damperhousing 227 causes the block element 225 to compress the dampener 229until the mechanical stop 260 is engaged, i.e. when the stop damper 270of the mechanical stop 260 engages the damper housing 227 as illustratedin FIG. 12B. It will be clear to the person skilled in the art that thestop damper 270 may also be arranged on the surface of the damperhousing 227 which the mechanical stop 260 of the damper piston 250contacts. The stop damper 270 will provide the same function regardlessof it specific mounting as long as it is interposed between the twosurfaces which would otherwise engage when the mechanical stop 260 isengaged, such that said surfaces engage the stop damper 270. Inembodiments the stop damper 270 is an integrated part of the mechanicalstop 260. In other embodiments the stop damper 270 may be a separatepart arranged such that the movement of the piston of the mechanicalbrake cylinder causes the stop damper 270 to come into contact with themechanical stop 260; in such embodiments the engagement of themechanical stop and the beginning of the second phase takes place oncecompression of the stop damper 270 is caused by the continuedapplication of pressure to the brake pedal.

Like the dampener 229, the stop damper 270 may be made from an elastomermaterial, such as nitril, silicone, fluorosilicone, neoprene,polyacrylate, polyurethane, polyisoprene and similar material.Alternatively, the stop damper 270 may be a different structure such asa spring which will also resiliently provide resistance for the axialmovement of the piston in the direction towards the stop damper 270. Insome embodiments of the invention the stop damper 270 may be made fromthe same material as the dampener 229. In such embodiments the forcerequired to move the mechanical piston further in the axial directiontoward the stop damper 270 and the dampener 229 after engagement of themechanical stop is increased as such movement requires compression ofboth the stop damper 270 and the dampener 229 during the second phase.

In some alternative embodiments comprising a stop damper 270, the stopdamper 270 is made of a resilient structure which requires a differentforce to compress than what is required to compress the dampener 229. Inone embodiment, the stop damper 270 requires a higher force to compressthan the dampener 229. Within an embodiment of the invention the stopdamper 270 has a Shore A hardness exceeding the Shore A hardness of thedampener 229. For example, the Shore A hardness of the stop damper 270may be in the range of 80-100 when measured according to ASTM D2240. Insome embodiments the stop damper 270 may be an elastomer material whilethe dampener 229 is a form of spring as previously discussed. Theresistance felt by the user in the second phase of the braking may bevaried in the same brake system by exchanging the stop damper 270 withanother stop damper 270 having a different Shore A hardness.

As the stop damper 270 and the dampener 229 together are harder tocompress than the dampener 229 alone, the user applying force to thesystem will experience resistance at two different levels before andafter engaging the mechanical stop 260, i.e. the user will experiencetwo-phase braking wherein some compression may take place during thesecond phase. The sensor 109 of the mechanical cylinder can detect theapplied force as previously described for the mechanical brake cylinders301. During the second phase of the braking, the user will need tocompress the stop damper 270 to affect the sensor 109, e.g. by movingthe first end of the cylinder rod 305′ towards the sensor 109, hence inthe second phase the user will need to apply greater force than in thefirst phase to achieve a change in the detected signal. This emulatesboth the feeling and the effect of a hydraulic brake cylinder, whereinforce applied after the mechanical stop 260 has been engage isdetectable by the brake system and wherein the force necessary toincrease the braking signal is higher in the second phase than in thefirst phase of the braking action.

A central principle to all of the discussed embodiments of the inventionis that a piston when moved in the axial direction towards a dampeningdevice will compress that dampening device, the dampening device in turnprovides resistance to the movement of the piston in that axialdirection. A mechanical stop is present and limits the movement of thepiston in the axial direction towards the dampening device. Thisprinciple is illustrated conceptually in FIGS. 13A and 13B. While thethree elements of the invention discussed for the general concept, i.e.the dampening device 440, the piston 450 having a mechanical stop 460,and the stopping structure 470, have been discussed in specificembodiments it is to be understood that the invention is not limited tothese specific embodiments, but may take various forms that provide thesame functionality.

FIG. 13A illustrates a default position where the dampening device 440is not compressed. FIG. 13B illustrates a situation where the piston 450has been moved in the direction towards the dampening device 440 untilthe mechanical stop 460 has engaged the stopping structure 470 and inwhich position the dampening device 440 is providing resistance againstthe movement of the piston, e.g. by elastic deformation.

The dampening device 440 may for example be a brake cylinder house ordamper house with a dampener 229 inside as previously described. Such adampener 229 may be an elastomer, a spring or a hydraulic damper such asan oil or gas damper. Alternative variants of the dampening device 440may be a resilient dampener such as an elastomer material or a springarranged without a housing. For example, an elastomer may be mountedaround a bar interposed between part of the piston 450 and a backplateor be fixedly attached to such a bar. In yet another exemplaryalternative the dampening device 440 may be a resilient elastomermounted in a shell structure such as a half-sphere.

The stopping structure 470 may be any sort of structure which limits thecontinued movement of the piston 450 in the axial direction toward thedampening device 440 once the mechanical stop 460 of the piston 450engages the stopping structure 470. Hence in variants of the inventionthe mechanical stop may be considered to comprise two parts, i.e. afirst part 460 of the piston 450 and a second part which is the stoppingstructure 470 which the piston 450 engages. In some variants thestopping structure 470 may be part of the dampening device 440, e.g.where the dampening device is a housing with a resilient structure andthe housing may act as the stopping structure 470 which the pistonengages. In other variants the stopping structure 470 may be arrangedadjacent to the dampening device 440. In one embodiment, the stoppingstructure 470 may be one or more bars adjacent to a resilient structureor it may be part of a shell structure, such as a half-sphere holdingthe resilient structure. In another example the stopping structure 470may be a bar extending partially into a cylindrical cavity of theresilient structure, e.g. it may be a bar around which a spring ismounted. In some variants the part of the piston 450 forming themechanical stop 260′ is at least part of the piston element whichengages the resilient structure of the dampening device 440. In othervariants the mechanical stop part of the piston 450 may be a protrusionfrom the part of the piston element engaging the resilient structure ofthe dampening device 440. In yet other variants the stopping structure470 may be located independently of the dampening device 440, forexample the piston 450 may comprise a protrusion from the piston rodforming the mechanical block 460′ of the piston engaging the other partof the stopping structure 470 which may be mounted independently of thedampening device 440.

It is to be understood that while the piston in the conceptualillustration of FIGS. 13A and 13B shows a rod with a piston element, thepiston may take any other shape, e.g. it may be a rod with a continuouscross section, it may be tapered or have various protrusions and/orflanges. In some variants the piston 450 may be the pedal itself. Forexample, the back of the pedal may be connected directly to a dampeningdevice 440 such as a spring. In such a variant the movement of the pedalmay directly be blocked by a stopping structure 470 in the form of astructure limiting the further angular movement of the pedal, such as apillar, a cylindrical structure around part of the resilient member or ascrew at the mounting plate on which the pedal is fastened.

The foregoing description has been presented for purposes ofillustration. It is not exhaustive and does not limit the invention tothe precise forms or embodiments disclosed. Modifications andadaptations of the invention will be apparent to those skilled in theart from consideration of the specification and practice of thedisclosed embodiments of the invention.

Other embodiments of the invention will be apparent to those skilled inthe art from consideration of the specification and practice of theinvention disclosed herein. It is intended that the specification andexamples be considered as exemplary only, with a true scope and spiritof the invention being indicated by the following claims.

We claim:
 1. A brake cylinder configured to provide brake signalling toan automotive simulator, the brake cylinder comprising: a pistonconfigured to move in an axial direction; a dampening device configuredto provide resistance to the piston when the piston moves in an axialdirection toward the dampening device; at least one sensor configured tomeasure a response to movement of said piston and send a signal to aprocessor of the automotive simulator indicative of that movement;wherein said piston comprises a mechanical stop configured to limit saidaxial movement of the piston in the axial direction.
 2. A brake cylinderaccording to claim 1, the dampening device comprising: a damper housingand a resilient damper arranged within the damper housing, the pistonbeing configured to move a block in the axial direction at leastpartially into the damper housing towards said resilient damper.
 3. Thebrake cylinder according to claim 2, wherein said mechanical stop isconfigured to limit said axial movement of said block in the directiontowards said resilient damper.
 4. The brake cylinder according to claim2, wherein the mechanical stop is configured to limit the axial movementof said block by contact between said mechanical stop and said damperhousing.
 5. The brake cylinder according to claim 1, wherein the pistonis configured to be mechanically connected to a brake pedal.
 6. Thebrake cylinder according to claim 2, wherein the piston further includesa threaded nut, the block is disposed between the damper and thethreaded nut, and the threaded nut is configured to adjust the responseof a brake pedal.
 7. The brake cylinder according to claim 2, the damperhousing further comprising a damper housing cap, the damper housing capbeing adjustably connected to the end of the damper housing such thatthe adjustment of the connection changes the length of a chamber withinthe damper housing wherein the damper is located.
 8. The brake cylinderaccording to claim 2, the damper housing further comprising a damperbracket, the damper bracket comprising at least one protrusion forming amechanical stop for engaging the mechanical stop of the block.
 9. Thebrake cylinder according to claim 1, wherein the at least one sensor isa load cell, a strain gauge, a rotary potentiometer, a hall effectsensor or a pressure sensor, said sensor may be present in combinationwith one or more additional sensors of any of the mentioned types. 10.The brake cylinder according to claim 1, wherein the brake cylindercomprises a stop damper, the stop damper being configured to provideresistance to the piston when the piston moves in an axial directiontoward the dampening device upon engagement of the mechanical stop. 11.The brake cylinder according to claim 1, wherein the brake cylindercomprises a cylinder chamber.
 12. The brake cylinder according to claim11 wherein the piston includes: a rod at least partially disposed withinthe cylinder chamber; a brake pedal connector configured to attach saidrod to a brake pedal; and a brake arm adjuster configured to adjust thedistance between the brake pedal connector and the rod.
 13. The brakecylinder according to claim 11, wherein the cylinder chamber is a slavecylinder chamber, the piston is a slave cylinder piston and the brakecylinder further comprises: a master cylinder chamber and at least onechannel configured to provide fluid communication between the mastercylinder chamber and the slave cylinder chamber; a master piston atleast partially disposed within the master cylinder chamber, the masterpiston configured to pressurize fluid in the master cylinder chamberwhen a brake pedal is depressed effecting the translation of the masterpiston along the axis of the master cylinder; and the at least onesensor being a pressure sensor configured to measure the pressure insidethe brake cylinder, wherein, when pressurizing fluid is in the mastercylinder chamber, the master piston is configured to drive said fluidfrom the master cylinder chamber to the slave cylinder chamber via theat least one channel to increase pressure in the slave cylinder chamber.14. The brake cylinder according to claim 13, wherein the mastercylinder chamber and the slave cylinder chambers are adjacent and a wallis disposed between the master cylinder chamber and the slave cylinderchamber, wherein the axis of the master piston and the axis of the slavepiston are parallel to each other.
 15. The brake cylinder according toclaim 14, the at least one channel is an opening in the wall, saidopening configured to provide fluid communication between the mastercylinder chamber and the slave cylinder chamber.
 16. The brake cylinderaccording to claim 13, further comprising: a master spring connected tothe master piston, the master spring configured to bias the masterpiston towards a default position of the master piston; and/or a slavecylinder spring connected to the slave piston, the slave cylinder springconfigured to bias the slave piston towards a default position of theslave position.
 17. A brake system configured to provide brakesignalling to an automotive simulator, the brake system comprising: abase; a brake pedal pivotably connected to said base; and a brakecylinder according to claim 2 connected to the brake pedal.
 18. A brakesystem according to claim 17, wherein the brake cylinder is pivotablyconnected to the brake pedal.